Stochastic models of regulation of transcription in biological cells.

In this paper we study an important global regulation mechanism of transcription of biological cells using specific macro-molecules, 6S RNAs. The functional property of 6S RNAs is of blocking the transcription of RNAs when the environment of the cell is not favorable. We investigate the efficiency of this mechanism with a scaling analysis of a stochastic model. The evolution equations of our model are driven by the law of mass action and the total number of polymerases is used as a scaling parameter. Two regimes are analyzed: exponential phase when the environment of the cell is favorable to its growth, and the stationary phase when resources are scarce. In both regimes, by defining properly occupation measures of the model, we prove an averaging principle for the associated multi-dimensional Markov process on a convenient timescale, as well as convergence results for "fast" variables of the system. An analytical expression of the asymptotic fraction of sequestrated polymerases in stationary phase is in particular obtained. The consequences of these results are discussed.

Cutoff scores for the "Interest game", an application for the assessment of diminished interest in neurocognitive disorders.

Diminished interest is a core feature of apathy that shows high prevalence in people with Mild and Major Neurocognitive disorders (NCD). In the clinical setting, apathy is mainly assessed using clinical scales and questionnaires, but new technologies are starting to be employed to complement classical instruments. Here, we explored the performance of the "Interest game," a ludic application that assesses personal interests, in discriminating between persons with and without diminished interest based on the Apathy Diagnostic Criteria. Two hundred and twenty-seven elderly participants (56 healthy controls, 118 persons with mild-NCD, and 53 with major-NCD) completed the Interest game and were assessed by clinicians concerning the presence and the severity of apathy. Results showed that the application scores varied with the presence of apathy, the type of disorder, and the education level. Cutoff scores calculated for persons with Mild-NCD resulted in a sensitivity of 0.68 and a specificity of 0.65 for the main score index, suggesting the interest of employing this application in the clinical setting to complement the classical assessment.

The limitations and challenges in the assessment of executive dysfunction associated with real-world functioning: The opportunity of serious games.

Nowadays, there is a broad range of methods for detecting and evaluating executive dysfunction ranging from clinical interview to neuropsychological evaluation. Nevertheless, a critical issue of these assessments is the lack of correspondence of the neuropsychological test's results with real-world functioning. This paper proposes serious games as a new framework to improve the neuropsychological assessment of real-world functioning. We briefly discuss the contribution and limitations of current methods of evaluation of executive dysfunction (paper-and-pencil tests, naturalistic observation methods, and Information and Communications Technologies) to inform on daily life functioning. Then, we analyze what are the limitations of these methods to predict real-world performance: (1) A lack of appropriate instruments to investigate the complexity of real-world functioning, (2) the vast majority of neuropsychological tests assess well-structured tasks, and (3) measurement of behaviors are based on simplistic data collection and statistical analysis. This work shows how serious games offer an opportunity to develop more efficient tools to detect executive dysfunction in everyday life contexts. Serious games provide meaningful narrative stories and virtual or real environments that immerse the user in natural and social environments with social interactions. In those highly interactive game environments, the player needs to adapt his/her behavioral performance to novel and ill-structured tasks which are suited for collecting user interaction evidence. Serious games offer a novel opportunity to develop better tools to improve diagnosis of the executive dysfunction in everyday life contexts. However, more research is still needed to implement serious games in everyday clinical practice.

Feasibility Study of an Internet-Based Platform for Tele-Neuropsychological Assessment of Elderly in Remote Areas.

Today, in rural isolated areas or so-called 'medical deserts', access to diagnosis and care is very limited. With the current pandemic crisis, now even more than ever, telemedicine platforms are gradually more employed for remote medical assessment. Only a few are tailored to comprehensive teleneuropsychological assessment of older adults. Hence, our study focuses on evaluating the feasibility of performing a remote neuropsychological assessment of older adults suffering from a cognitive complaint. 50 participants (aged 55 and older) were recruited at the local hospital of Digne-les-Bains, France. A brief neuropsychological assessment including a short clinical interview and several validated neuropsychological tests was administered in two conditions, once by Teleneuropsychology (TNP) and once by Face-to-Face (FTF) in a crossover design. Acceptability and user experience was assessed through questionnaires. Results show high agreement in most tests between the FTF and TNP conditions. The TNP was overall well accepted by the participants. However, differences in test performances were observed, which urges the need to validate TNP tests with broader samples with normative data.

Remote cognitive assessment of older adults in rural areas by telemedicine and automatic speech and video analysis: protocol for a cross-over feasibility study.

INTRODUCTION: Early detection of cognitive impairments is crucial for the successful implementation of preventive strategies. However, in rural isolated areas or so-called 'medical deserts', access to diagnosis and care is very limited. With the current pandemic crisis, now even more than ever, remote solutions such as telemedicine platforms represent great potential and can help to overcome this barrier. Moreover, current advances made in voice and image analysis can help overcome the barrier of physical distance by providing additional information on a patients' emotional and cognitive state. Therefore, the aim of this study is to evaluate the feasibility and reliability of a videoconference system for remote cognitive testing empowered by automatic speech and video analysis. METHODS AND ANALYSIS: 60 participants (aged 55 and older) with and without cognitive impairment will be recruited. A complete neuropsychological assessment including a short clinical interview will be administered in two conditions, once by telemedicine and once by face-to-face. The order of administration procedure will be counterbalanced so half of the sample starts with the videoconference condition and the other half with the face-to-face condition. Acceptability and user experience will be assessed among participants and clinicians in a qualitative and quantitative manner. Speech and video features will be extracted and analysed to obtain additional information on mood and engagement levels. In a subgroup, measurements of stress indicators such as heart rate and skin conductance will be compared. ETHICS AND DISSEMINATION: The procedures are not invasive and there are no expected risks or burdens to participants. All participants will be informed that this is an observational study and their consent taken prior to the experiment. Demonstration of the effectiveness of such technology makes it possible to diffuse its use across all rural areas ('medical deserts') and thus, to improve the early diagnosis of neurodegenerative pathologies, while providing data crucial for basic research. Results from this study will be published in peer-reviewed journals.

Using Theories of Behavior Change to Develop Interventions for Healthy Aging.

Healthy aging requires people to adopt and maintain beneficial behaviors in all stages of the life span. Supporting behavior change, including via the motivation to make and maintain those changes, is therefore important for the promotion of healthy aging. The aim of this overview is to introduce theoretical frameworks from the psychology of motivation that lend themselves to the development of effective interventions promoting behavior change conducive to healthy aging. We discuss theoretical frameworks referring to the determinants, properties, and functionality of goals aimed at behavior change, and consider the implications of the various theories for designing interventions to support healthy aging. We first consider theories that focus on beliefs and attitudes as determinants of goals, then we address theories that focus on the structure and content as important properties of goals, and, finally, we examine theories drawing on conscious and nonconscious processes underlying the functionality of these goals. We will present if-then planning and mental contrasting, as well as nudging and boosting, that is, novel strategies of behavior change that support the creation of scalable interventions for healthy aging across the life span. Against this background, new perspectives emerge for modern, state-of-the-art, and individually tailored interventions with the aim of enhancing older people's healthy living.

Grasping Social Apathy: The Role of Reach-To-Grasp Action Kinematics for the Assessment of Social Apathy in Mild Neurocognitive Disorders.

BACKGROUND: Social apathy, a reduction in initiative in proposing or engaging in social activities or interactions, is common in mild neurocognitive disorders (MND). Current apathy assessment relies on self-reports or clinical scales, but growing attention is devoted to defining more objective, measurable and non-invasive apathy proxies. OBJECTIVE: In the present study we investigated the interest of recording action kinematics in a social reach-to-grasp task for the assessment of social apathy. METHODS: Thirty participants took part in the study: 11 healthy controls (HC; 6 females, mean age = 68.3±10.5 years) and 19 subjects with MND (13 females, mean age = 75.7±6.3 years). Based on the Diagnostic Criteria for Apathy, MND subjects were classified as socially apathetic (A-MND, N = 9) versus non-apathetic (NA-MND, N = 10). SensRing, a ring-shaped wearable sensor, was placed on their index finger, and subjects were asked to reach and grasp a can to place it into a cup (individual condition) and pass it to a partner (social condition). RESULTS: In the reach-to-grasp phase of the action, HC and NA-MND showed different acceleration and velocity profiles in the social versus individual condition. No differences were found for A-MND. CONCLUSION: Previous studies showed the interest of recording patients' level of weekly motor activity for apathy assessment. Here we showed that a 10-min reach-to-grasp task may provide information to differentiate socially apathetic and non-apathetic subjects with MND, thus providing a tool easily usable in the clinical practice. Future studies with a bigger sample are needed to better characterize these findings.

A French-Greek Cross-Site Comparison Study of the Use of Automatic Video Analyses for the Assessment of Autonomy in Dementia Patients.

BACKGROUND: At present, the assessment of autonomy in daily living activities, one of the key symptoms in Alzheimer's disease (AD), involves clinical rating scales. METHODS: In total, 109 participants were included. In particular, 11 participants during a pre-test in Nice, France, and 98 participants (27 AD, 38 mild cognitive impairment-MCI-and 33 healthy controls-HC) in Thessaloniki, Greece, carried out a standardized scenario consisting of several instrumental activities of daily living (IADLs), such as making a phone call or preparing a pillbox while being recorded. Data were processed by a platform of video signal analysis in order to extract kinematic parameters, detecting activities undertaken by the participant. RESULTS: The video analysis data can be used to assess IADL task quality and provide clinicians with objective measurements of the patients' performance. Furthermore, it reveals that the HC statistically significantly outperformed the MCI, which had better performance compared to the AD participants. CONCLUSIONS: Accurate activity recognition data for the analyses of the performance on IADL activities were obtained.

The "Interest Game": A Ludic Application to Improve Apathy Assessment in Patients with Neurocognitive Disorders.

BACKGROUND: Apathy, a highly prevalent behavioral disorder in Alzheimer's disease and other related disorders, is currently assessed using clinical scales as it is for all neuropsychiatric disorders. OBJECTIVE: The aim of this study is to propose a new type of assessment using new technologies designed to assess loss of interest by a more implicit and indirect method. METHODS: The Interest Game is a form of interactive self-report, where categories of interests are presented in order to quantify them and identify the activities that constitute them. Two indices can be extracted, the number of categories and the number of activities selected. We compared the scores between three groups: Apathetic (A) and Non-Apathetic (NA) subjects (according to the Apathy Diagnostic Criteria) and controls with no objective cognitive impairment. RESULTS: 95 subjects were included. Results showed that subjects from the A group had significantly less interests (both categories and images selected) than the NA group. As expected, the control group selected a higher number of categories than the other groups. The diagnosis (minor or major neurocognitive disorder) and level of education had also a significant effect on the number of categories selected. Furthermore, subjects with major neurocognitive disorder (NCD) had significantly less interests than minor NCD group. The number of categories measure was more sensitive than the number of images selected. CONCLUSION: The Interest Game is a promising tool to quantify and identify subject interests and differentiate between apathetic and non-apathetic subjects. Future studies should focus on including more apathetic subjects in the minor NCD group and validating this tool with the general population.

Assistive Technologies to Address Capabilities of People with Dementia: From Research to Practice.

Assistive technologies became pervasive and virtually present in all our life domains. They can be either an enabler or an obstacle leading to social exclusion. The Fondation Médéric Alzheimer gathered international experts of dementia care, with backgrounds in biomedical, human and social sciences, to analyze how assistive technologies can address the capabilities of people with dementia, on the basis of their needs. Discussion covered the unmet needs of people with dementia, the domains of daily life activities where assistive technologies can provide help to people with dementia, the enabling and empowering impact of technology to improve their safety and wellbeing, barriers and limits of use, technology assessment, ethical and legal issues. The capability approach (possible freedom) appears particularly relevant in person-centered dementia care and technology development. The focus is not on the solution, rather on what the person can do with it: seeing dementia as disability, with technology as an enabler to promote capabilities of the person, provides a useful framework for both research and practice. This article summarizes how these concepts took momentum in professional practice and public policies in the past 15 years (2000-2015), discusses current issues in the design, development and economic model of assistive technologies for people with dementia, and covers how these technologies are being used and assessed.

A stochastic analysis of autoregulation of gene expression.

This paper analyzes, in the context of a prokaryotic cell, the stochastic variability of the number of proteins when there is a control of gene expression by an autoregulation scheme. The goal of this work is to estimate the efficiency of the regulation to limit the fluctuations of the number of copies of a given protein. The autoregulation considered in this paper relies mainly on a negative feedback: the proteins are repressors of their own gene expression. The efficiency of a production process without feedback control is compared to a production process with an autoregulation of the gene expression assuming that both of them produce the same average number of proteins. The main characteristic used for the comparison is the standard deviation of the number of proteins at equilibrium. With a Markovian representation and a simple model of repression, we prove that, under a scaling regime, the repression mechanism follows a Hill repression scheme with an hyperbolic control. An explicit asymptotic expression of the variance of the number of proteins under this regulation mechanism is obtained. Simulations are used to study other aspects of autoregulation such as the rate of convergence to equilibrium of the production process and the case where the control of the production process of proteins is achieved via the inhibition of mRNAs.

Dementia beyond 2025: Knowledge and uncertainties.

Given that there may well be no significant advances in drug development before 2025, prevention of dementia-Alzheimer's disease through the management of vascular and lifestyle-related risk factors may be a more realistic goal than treatment. Level of education and cognitive reserve assessment in neuropsychological testing deserve attention, as well as cultural, social, and economic aspects of caregiving. Assistive technologies for dementia care remain complex. Serious games are emerging as virtual educational and pleasurable tools, designed for individual and cooperative skill building. Public policies are likely to pursue improving awareness and understanding of dementia; providing good quality early diagnosis and intervention for all; improving quality of care from diagnosis to the end of life, using clinical and economic end points; delivering dementia strategies quicker, with an impact on more people. Dementia should remain presented as a stand-alone concept, distinct from frailty or loss of autonomy. The basic science of sensory impairment and social engagement in people with dementia needs to be developed. E-learning and serious games programs may enhance public and professional education. Faced with funding shortage, new professional dynamics and economic models may emerge through coordinated, flexible research networks. Psychosocial research could be viewed as an investment in quality of care, rather than an academic achievement in a few centers of excellence. This would help provide a competitive advantage to the best operators. Stemming from care needs, a logical, systems approach to dementia care environment through organizational, architectural, and psychosocial interventions may be developed, to help reduce symptoms in people with dementia and enhance quality of life. Dementia-friendly environments, culture, and domesticity are key factors for such interventions.

Establishing assay sensitivity in QT studies: experience with the use of moxifloxacin in an early phase clinical pharmacology study and comparison with its effect in a thorough QT study.

OBJECTIVE: To compare the effect of moxifloxacin as a positive control in a single ascending dose (SAD) study with that in a thorough QT (TQT) study. METHODS: Moxifloxacin was used as a positive control in a SAD study and a TQT study during the evaluation of the QT liability of a new drug. The SAD study had enrolled 24 males and the TQT study 25 males. Both studies intensively monitored electrocardiograms (ECGs) and pharmacokinetic sampling. Effect of moxifloxacin on QTc interval was analysed in each study by intersection union test (IUT) and by exposure-response (ER) analysis and the results compared. Cost-effectiveness of this approach was computed. RESULTS: Analysis by IUT revealed that the maximum mean (90 % confidence interval (CI)) placebo-corrected change from baseline (ΔΔQTcF) in the SAD study and the TQT study were remarkably similar (10.7 (6.5; 14.9) ms vs. 9.09 (6.20; 11.98) ms, respectively). In both studies, assay sensitivity was established by the 90 % lower bound exceeding 5 ms. ER analysis revealed the slopes in both studies to be significantly different from zero and comparable. Bootstrap-predicted effects of moxifloxacin at geometric mean concentrations of ~3000 ng/mL were 8.19 (90 % CI 5.86; 10.7) ms in the SAD study and 7.33 (90 % CI 5.69; 9.70) ms in the TQT study. CONCLUSION: Moxifloxacin can be integrated effectively in a SAD study to establish assay sensitivity, and a TQT study may be replaced by a SAD study which has the required assay sensitivity. Further experience is warranted to verify this conclusion.

Assessment of mTOR-Dependent Translational Regulation of Interferon Stimulated Genes.

Type-I interferon (IFN)-induced activation of the mammalian target of rapamycin (mTOR) signaling pathway has been implicated in translational control of mRNAs encoding interferon-stimulated genes (ISGs). However, mTOR-sensitive translatomes commonly include mRNAs with a 5' terminal oligopyrimidine tract (TOP), such as those encoding ribosomal proteins, but not ISGs. Because these translatomes were obtained under conditions when ISG expression is not induced, we examined the mTOR-sensitive translatome in human WISH cells stimulated with IFN ß. The mTOR inhibitor Torin1 resulted in a repression of global protein synthesis, including that of ISG products, and translation of all but 3 ISG mRNAs (TLR3, NT5C3A, and RNF19B) was not selectively more sensitive to mTOR inhibition. Detailed studies of NT5C3A revealed an IFN-induced change in transcription start site resulting in a switch from a non-TOP to a TOP-like transcript variant and mTOR sensitive translation. Thus, we show that, in the cell model used, translation of the vast majority of ISG mRNAs is not selectively sensitive to mTOR activity and describe an uncharacterized mechanism wherein the 5'-UTR of an mRNA is altered in response to a cytokine, resulting in a shift from mTOR-insensitive to mTOR-sensitive translation.

Ecological Assessment of Autonomy in Instrumental Activities of Daily Living in Dementia Patients by the Means of an Automatic Video Monitoring System.

Currently, the assessment of autonomy and functional ability involves clinical rating scales. However, scales are often limited in their ability to provide objective and sensitive information. By contrast, information and communication technologies may overcome these limitations by capturing more fully functional as well as cognitive disturbances associated with Alzheimer disease (AD). We investigated the quantitative assessment of autonomy in dementia patients based not only on gait analysis but also on the participant performance on instrumental activities of daily living (IADL) automatically recognized by a video event monitoring system (EMS). Three groups of participants (healthy controls, mild cognitive impairment, and AD patients) had to carry out a standardized scenario consisting of physical tasks (single and dual task) and several IADL such as preparing a pillbox or making a phone call while being recorded. After, video sensor data were processed by an EMS that automatically extracts kinematic parameters of the participants' gait and recognizes their carried out activities. These parameters were then used for the assessment of the participants' performance levels, here referred as autonomy. Autonomy assessment was approached as classification task using artificial intelligence methods that takes as input the parameters extracted by the EMS, here referred as behavioral profile. Activities were accurately recognized by the EMS with high precision. The most accurately recognized activities were "prepare medication" with 93% and "using phone" with 89% precision. The diagnostic group classifier obtained a precision of 73.46% when combining the analyses of physical tasks with IADL. In a further analysis, the created autonomy group classifier which obtained a precision of 83.67% when combining physical tasks and IADL. Results suggest that it is possible to quantitatively assess IADL functioning supported by an EMS and that even based on the extracted data the groups could be classified with high accuracy. This means that the use of such technologies may provide clinicians with diagnostic relevant information to improve autonomy assessment in real time decreasing observer biases.

Development of an international schedule for the assessment and staging of care for dementia.

BACKGROUND: A reliable and valid global staging scale has been lacking within dementia care. OBJECTIVE: To develop an easy-to-use multi-dimensional clinical staging schedule for dementia. METHODS: The schedule was developed through: i) Two series of focus groups (40 and 48 participants, respectively) in Denmark, France, Germany, Netherlands, Spain, Switzerland, and UK with a multi-disciplinary group of professionals working within dementia care, to assess the need for a dementia-staging tool and to obtain suggestions on its design and characteristics; ii) A pilot-study over three rounds to test inter-rater reliability of the newly developed schedule using written case histories, with five members of the project's steering committee and 27 of their colleagues from Netherlands, France, and Spain as participants; and iii) A field-study to test the schedule's inter-rater reliability in clinical practice in France, Germany, Netherlands, Spain, Italy, Turkey, South Korea, Romania, and Serbia, which included 209 dementia patients and 217 of their caregivers as participants. RESULTS: Focus group participants indicated a clear need for a culture-fair international dementia staging scale and reached consensus on face validity and content validity. Accordingly, the schedule has been composed of seven dimensions including behavioral, cognitive, physical, functional, social, and care aspects. Overall, the schedule showed adequate face validity, content validity, and inter-rater reliability; in the nine field-sites, intraclass correlation coefficients (ICCs; absolute agreement) for individual dimensions ranged between 0.38 and 1.0, with 84.4% of ICCs over 0.7. ICCs for total sum scores ranged between 0.89 and 0.99 in the nine field-sites. CONCLUSION: The IDEAL schedule looks promising as tool for the clinical and social management of people with dementia globally, though further reliability and validity testing is needed.

Validation of the relevant outcome scale for Alzheimer's disease: a novel multidomain assessment for daily medical practice.

INTRODUCTION: The Relevant Outcome Scale for Alzheimer's Disease (ROSA) is a new observer rating instrument recently developed for routine medical practice. The validity and reliability of ROSA as well as sensitivity to changes due to intervention were examined in an open-label, single-arm, multicenter clinical study in patients with Alzheimer's disease (AD). METHODS: The study enrolled 471 patients with a diagnosis of AD consistent with the criteria of the National Institute of Neurological and Communicative Disease and Stroke/Alzheimer's Disease and Related Disorders Association or with the Diagnostic and Statistical Manual Disorders criteria for dementia of Alzheimer's type. Following assessments of the ROSA and other standard assessments (Alzheimer's Disease Assessment Scale - cognitive subscale, Severe Impairment Battery, Neuropsychiatric Inventory, and Disability Assessment for Dementia), patients were treated with memantine for 12 weeks. Factor analysis of the baseline ROSA total scores was performed based on the principal components method using the varimax orthogonal rotational procedure. The psychometric analyses of the ROSA included internal consistency, test-retest reliability, inter-rater reliability, construct validity, and responsiveness to changes over time. RESULTS: All items showed adequate factor loadings and were retained in the final ROSA as Factor 1 (all items related to cognition, communication, function, quality of life and caregiver burden) and Factor 2 (all behavior items). The ROSA demonstrated high internal consistency (Cronbach's α = 0.93), test-retest reliability (intraclass correlation coefficient = 0.93), and inter-rater reliability (intraclass correlation coefficient = 0.91). The correlation coefficients between the ROSA and each of the validated scales ranged between 0.4 and 0.7, confirming the ROSA construct validity. Nonsubstantial floor and ceiling effects were found in middle and late disease stages, whereas a small ceiling effect was observed in the early stage. The ROSA responsiveness to change was high (responsiveness index ≥0.8) for all severity stages. CONCLUSIONS: The ROSA is a valid and reliable instrument to aid medical practitioners in sensitively assessing AD-relevant symptoms over time in their clinical practice.