The Effects of Visual Affordances and Feedback on a Gesture-based Interaction with Novice Users

This dissertation studies the roles and effects of visual affordances and feedback in a general-purpose gesture interface for novice users. Gesture interfaces are popularly viewed as intuitive and user-friendly modes of interacting with computers and robots, but they in fact introduce many challenges for users not already familiar with the system. Affordances and feedback – two fundamental building blocks of interface design – are perfectly suited to address the most important challenges and questions for novices using a gesture interface: what can they do? how do they do it? are they being understood? has anything gone wrong? Yet gesture interfaces rarely incorporate these features in a deliberate manner, and there are presently no well-adopted guidelines for designing affordances and feedback for gesture interaction, nor any clear understanding of their effects on such an interaction. A general-purpose gesture interaction system was developed based on a virtual touchscreen paradigm, and guided by a novel gesture interaction framework. This framework clarifies the relationship between gesture interfaces and the application interfaces they support, and it provides guidance for selecting and designing appropriate affordances and feedback. Using this gesture system, a 40-person (all novices) user study was conducted to evaluate the effects on interaction performance and user satisfaction of four categories of affordances and feedback. The experimental results demonstrated that affordances indicating how to do something in a gesture interaction are more important to interaction performance than affordances indicating what can be done, and also that system status is more important than feedback acknowledging user actions. However, the experiments also showed unexpectedly high interaction performance when affordances and feedback were omitted. The explanation for this result remains an open question, though several potential causes are analyzed, and a tentative interpretation is provided. The main contributions of this dissertation to the HRI and HCI research communities are 1) the design of a virtual touchscreen-based interface for general-purpose gesture interaction, to serve as a case study for identifying and designing affordances and feedback for gesture interfaces; 2) the method and surprising results of an evaluation of distinct affordance and feedback categories, in particular their effects on a gesture interaction with novice users; and 3) a set of guidelines and insights about the relationship between a user, a gesture interface, and a generic application interface, centered on a novel interaction framework that may be used to design and study other gesture systems. In addition to the intellectual contributions, this work is useful to the general public because it may influence how future assistive robots are designed to interact with people in various settings including search and rescue, healthcare and elderly care

The Effects of Visual Affordances and Feedback on a Gesture-based Interaction with Novice Users

This dissertation studies the roles and effects of visual affordances and feedback in a general-purpose gesture interface for novice users. Gesture interfaces are popularly viewed as intuitive and user-friendly modes of interacting with computers and robots, but they in fact introduce many challenges for users not already familiar with the system. Affordances and feedback – two fundamental building blocks of interface design – are perfectly suited to address the most important challenges and questions for novices using a gesture interface: what can they do? how do they do it? are they being understood? has anything gone wrong? Yet gesture interfaces rarely incorporate these features in a deliberate manner, and there are presently no well-adopted guidelines for designing affordances and feedback for gesture interaction, nor any clear understanding of their effects on such an interaction. A general-purpose gesture interaction system was developed based on a virtual touchscreen paradigm, and guided by a novel gesture interaction framework. This framework clarifies the relationship between gesture interfaces and the application interfaces they support, and it provides guidance for selecting and designing appropriate affordances and feedback. Using this gesture system, a 40-person (all novices) user study was conducted to evaluate the effects on interaction performance and user satisfaction of four categories of affordances and feedback. The experimental results demonstrated that affordances indicating how to do something in a gesture interaction are more important to interaction performance than affordances indicating what can be done, and also that system status is more important than feedback acknowledging user actions. However, the experiments also showed unexpectedly high interaction performance when affordances and feedback were omitted. The explanation for this result remains an open question, though several potential causes are analyzed, and a tentative interpretation is provided. The main contributions of this dissertation to the HRI and HCI research communities are 1) the design of a virtual touchscreen-based interface for general-purpose gesture interaction, to serve as a case study for identifying and designing affordances and feedback for gesture interfaces; 2) the method and surprising results of an evaluation of distinct affordance and feedback categories, in particular their effects on a gesture interaction with novice users; and 3) a set of guidelines and insights about the relationship between a user, a gesture interface, and a generic application interface, centered on a novel interaction framework that may be used to design and study other gesture systems. In addition to the intellectual contributions, this work is useful to the general public because it may influence how future assistive robots are designed to interact with people in various settings including search and rescue, healthcare and elderly care

Glutamate receptor mutations in psychiatric and neurodevelopmental disorders

Alterations in glutamatergic neurotransmission have long been associated with psychiatric and neurodevelopmental disorders (PNDD), but only recent advances in high-throughput DNA sequencing have allowed interrogation of the prevalence of mutations in glutamate receptors (GluR) among afflicted individuals. In this review we discuss recent work describing GluR mutations in the context of PNDDs. Although there are no strict relationships between receptor subunit or type and disease, some interesting preliminary conclusions have arisen. Mutations in genes coding for ionotropic glutamate receptor subunits, which are central to synaptic transmission and plasticity, are mostly associated with intellectual disability and autism spectrum disorders. In contrast, mutations of metabotropic GluRs, having a role on modulating neural transmission, are preferentially associated with psychiatric disorders. Also, the prevalence of mutations among GluRs is highly heterogeneous, suggesting a critical role of certain subunits in PNDD pathophysiology. The emerging bias between GluR subtypes and specific PNDDs may have clinical implications

Ghrelin Gene Variants Influence on Metabolic Syndrome Components in Aged Spanish Population

BACKGROUND: The role of genetic variations within the ghrelin gene on cardiometabolic profile and nutritional status is still not clear in humans, particularly in elderly people. OBJECTIVES: We investigated six SNPs of the ghrelin gene and their relationship with metabolic syndrome (MS) components. SUBJECTS AND METHODS: 824 subjects (413 men/411 women, age 77.31±5.04) participating in the Mataró aging study (n = 310) and the Hortega study (n = 514) were analyzed. Anthropometric variables, ghrelin, lipids, glucose and blood pressure levels were measured, and distribution of SNPs -994CT (rs26312), -604GA (rs27647), -501AC (rs26802), R51Q (rs34911341), M72L (rs696217) and L90G (rs4684677) of the ghrelin gene evaluated. Genotypes were determined by multiplex PCR and SNaPshot minisequencing. MS (IDF criteria) was found in 54.9%.RESULTS:No association between any of the SNPs and levels of total fasting circulating ghrelin levels was found. C/A-A/A genotype of M72L was associated with increased risk of central obesity according to IDF criteria, while G/A-G/G genotypes of -604GA with reduced risk. A/A genotype of -501AC polymorphism was associated to decreased BMI. In relation to lipid profile, the same genotypes of -604GA were associated with increased total cholesterol and LDL-cholesterol and -501AC with reduced triglycerides. There were no associations with systolic or diastolic blood pressure levels or with hypertension, glucose levels or diabetes and ghrelin polymorphisms. However, G/G genotype of -604GA was associated with glucose >100 mg/dL. Haplotype analysis showed that only one haplotype is associated with increased risk of waist circumference and central obesity. The analysis of subjects by gender showed an important and different association of these polymorphisms regarding MS parameters. CONCLUSION: Ghrelin gene variants -604GA, -501AC and M72L are associated with certain components of MS, in particular to BMI and lipid profile in elderly Spanish subject

Glutamate receptor mutations in psychiatric and neurodevelopmental disorders

Altres ajuts: Programa "Ramón y Cajal" i Programa "Miquel Servet"Alterations in glutamatergic neurotransmission have long been associated with psychiatric and neurodevelopmental disorders (PNDD), but only recent advances in high-throughput DNA sequencing have allowed interrogation of the prevalence of mutations in glutamate receptors (GluR) among afflicted individuals. In this review we discuss recent work describing GluR mutations in the context of PNDDs. Although there are no strict relationships between receptor subunit or type and disease, some interesting preliminary conclusions have arisen. Mutations in genes coding for ionotropic glutamate receptor subunits, which are central to synaptic transmission and plasticity, are mostly associated with intellectual disability and autism spectrum disorders. In contrast, mutations of metabotropic GluRs, having a role on modulating neural transmission, are preferentially associated with psychiatric disorders. Also, the prevalence of mutations among GluRs is highly heterogeneous, suggesting a critical role of certain subunits in PNDD pathophysiology. The emerging bias between GluR subtypes and specific PNDDs may have clinical implications

High Zika Virus Seroprevalence in Salvador, Northeastern Brazil Limits the Potential for Further Outbreaks.

During 2015 to 2016, Brazil reported more Zika virus (ZIKV) cases than any other country, yet population exposure remains unknown. Serological studies of ZIKV are hampered by cross-reactive immune responses against heterologous viruses. We conducted serosurveys for ZIKV, dengue virus (DENV), and Chikungunya virus (CHIKV) in 633 individuals prospectively sampled during 2015 to 2016, including microcephaly and non-microcephaly pregnancies, HIV-infected patients, tuberculosis patients, and university staff in Salvador in northeastern Brazil using enzyme-linked immunosorbent assays (ELISAs) and plaque reduction neutralization tests. Sera sampled retrospectively during 2013 to 2015 from 277 HIV-infected patients were used to assess the spread of ZIKV over time. Individuals were georeferenced, and sociodemographic indicators were compared between ZIKV-positive and -negative areas and areas with and without microcephaly cases. Epidemiological key parameters were modeled in a Bayesian framework. ZIKV seroprevalence increased rapidly during 2015 to 2016, reaching 63.3% by 2016 (95% confidence interval [CI], 59.4 to 66.8%), comparable to the seroprevalence of DENV (75.7%; CI, 69.4 to 81.1%) and higher than that of CHIKV (7.4%; CI, 5.6 to 9.8%). Of 19 microcephaly pregnancies, 94.7% showed ZIKV IgG antibodies, compared to 69.3% of 257 non-microcephaly pregnancies (P = 0.017). Analyses of sociodemographic data revealed a higher ZIKV burden in low socioeconomic status (SES) areas. High seroprevalence, combined with case data dynamics allowed estimates of the basic reproduction number R0 of 2.1 (CI, 1.8 to 2.5) at the onset of the outbreak and an effective reproductive number Reff of <1 in subsequent years. Our data corroborate ZIKV-associated congenital disease and an association of low SES and ZIKV infection and suggest that population immunity caused cessation of the outbreak. Similar studies from other areas will be required to determine the fate of the American ZIKV outbreak.IMPORTANCE The ongoing American Zika virus (ZIKV) outbreak involves millions of cases and has a major impact on maternal and child health. Knowledge of infection rates is crucial to project future epidemic patterns and determine the absolute risk of microcephaly upon maternal ZIKV infection during pregnancy. For unknown reasons, the vast majority of ZIKV-associated microcephaly cases are concentrated in northeastern Brazil. We analyzed different subpopulations from Salvador, a Brazilian metropolis representing one of the most affected areas during the American ZIKV outbreak. We demonstrate rapid spread of ZIKV in Salvador, Brazil, and infection rates exceeding 60%. We provide evidence for the link between ZIKV and microcephaly, report that ZIKV predominantly affects geographic areas with low socioeconomic status, and show that population immunity likely caused cessation of the outbreak. Our results enable stakeholders to identify target populations for vaccination and for trials on vaccine efficacy and allow refocusing of research efforts and intervention strategies

How reliably can algorithms identify eosinophilic asthma phenotypes using non-invasive biomarkers?

Asthma is a heterogeneous respiratory disease that encompasses different inflammatory and functional endophenotypes. Many non-invasive biomarkers has been investigated to its pathobiology. Heany et al proposed a clinical algorithm that classifies severe asthmatic patients into likely-eosinophilic phenotypes, based on accessible biomarkers: PBE, current treatment, FeNO, presence of nasal polyps (NP) and age of onset.We assessed the concordance between the algorithm proposed by Heany et al. with sputum examination, the gold standard, in 145 asthmatic patients of the MEGA cohort with varying grades of severity.No correlation was found between both classifications 0.025 (CI = 0.013-0.037). Moreover, no relationship was found between sputum eosinophilia and peripheral blood eosinophilia count in the total studied population.In conclusion, our results suggest that grouping the biomarkers proposed by Heany et al. are insufficient to diagnose eosinophilic phenotypes in asthmatic patients. Sputum analysis remains the gold standard to assess airway inflammation.© 2022 The Authors. Clinical and Translational Allergy published by John Wiley & Sons Ltd on behalf of European Academy of Allergy and Clinical Immunology

Tumors defective in homologous recombination rely on oxidative metabolism: relevance to treatments with PARP inhibitors

Mitochondrial metabolism and the generation of reactive oxygen species (ROS) contribute to the acquisition of DNA mutations and genomic instability in cancer. How genomic instability influences the metabolic capacity of cancer cells is nevertheless poorly understood. Here, we show that homologous recombination-defective (HRD) cancers rely on oxidative metabolism to supply NAD+ and ATP for poly(ADP-ribose) polymerase (PARP)-dependent DNA repair mechanisms. Studies in breast and ovarian cancer HRD models depict a metabolic shift that includes enhanced expression of the oxidative phosphorylation (OXPHOS) pathway and its key components and a decline in the glycolytic Warburg phenotype. Hence, HRD cells are more sensitive to metformin and NAD+ concentration changes. On the other hand, shifting from an OXPHOS to a highly glycolytic metabolism interferes with the sensitivity to PARP inhibitors (PARPi) in these HRD cells. This feature is associated with a weak response to PARP inhibition in patient-derived xenografts, emerging as a new mechanism to determine PARPi sensitivity. This study shows a mechanistic link between two major cancer hallmarks, which in turn suggests novel possibilities for specifically treating HRD cancers with OXPHOS inhibitors

Efficacy and Safety of Ixekizumab in the Treatment of Radiographic Axial Spondyloarthritis:Sixteen-Week Results From a Phase III Randomized, Double-Blind, Placebo-Controlled Trial in Patients With Prior Inadequate Response to or Intolerance of Tumor Necrosis Factor Inhibitors

Objective: To investigate the efficacy and safety of ixekizumab in patients with active radiographic axial spondyloarthritis (SpA) and prior inadequate response to or intolerance of 1 or 2 tumor necrosis factor inhibitors (TNFi). Methods: In this phase III randomized, double-blind, placebo-controlled trial, adult patients with an inadequate response to or intolerance of 1 or 2 TNFi and an established diagnosis of axial SpA (according to the Assessment of SpondyloArthritis international Society [ASAS] criteria for radiographic axial SpA, with radiographic sacroiliitis defined according to the modified New York criteria and ≥1 feature of SpA) were recruited and randomized 1:1:1 to receive placebo or 80-mg subcutaneous ixekizumab every 2 weeks (IXEQ2W) or 4 weeks (IXEQ4W), with an 80-mg or 160-mg starting dose. The primary end point was 40% improvement in disease activity according to the ASAS criteria (ASAS40) at week 16. Secondary outcomes and safety were also assessed. Results: A total of 316 patients were randomized to receive placebo (n = 104), IXEQ2W (n = 98), or IXEQ4W (n = 114). At week 16, significantly higher proportions of IXEQ2W patients (n = 30 [30.6%]; P = 0.003) or IXEQ4W patients (n = 29 [25.4%]; P = 0.017) had achieved an ASAS40 response versus the placebo group (n = 13 [12.5%]), with statistically significant differences reported as early as week 1 with ixekizumab treatment. Statistically significant improvements in disease activity, function, quality of life, and spinal magnetic resonance imaging–evident inflammation were observed after 16 weeks of ixekizumab treatment versus placebo. Treatment-emergent adverse events (AEs) with ixekizumab treatment were more frequent than with placebo. Serious AEs were similar across treatment arms. One death was reported (IXEQ2W group). Conclusion: Ixekizumab treatment for 16 weeks in patients with active radiographic axial SpA and previous inadequate response to or intolerance of 1 or 2 TNFi yields rapid and significant improvements in the signs and symptoms of radiographic axial SpA versus placebo