Best Model Identification: A Rested Bandit Formulation

We introduce and analyze a best arm identification problem in the rested bandit setting, wherein arms are themselves learning algorithms whose expected losses decrease with the number of times the arm has been played. The shape of the expected loss functions is similar across arms, and is assumed to be available up to unknown parameters that have to be learned on the fly. We define a novel notion of regret for this problem, where we compare to the policy that always plays the arm having the smallest expected loss at the end of the game. We analyze an arm elimination algorithm whose regret vanishes as the time horizon increases. The actual rate of convergence depends in a detailed way on the postulated functional form of the expected losses. We complement our analysis with lower bounds, indicating strengths and limitations of the proposed solution

Maternal alexithymia and attachment style: Which relationship with their children's headache features and psychological profile?

Introduction: A growing body of literature has shown an association between somatic symptoms and insecure "attachment style." In a recent study, we found a relationship between migraine severity, ambivalent attachment style, and psychological symptoms in children/adolescents. There is evidence that caregivers' attachment styles and their way of management/expression of emotions can influence children's psychological profile and pain expression. To date, data dealing with headache are scarce. Our aim was to study the role of maternal alexithymia and attachment style on their children's migraine severity, attachment style, and psychological profile. Materials and methods: We enrolled 84 consecutive patients suffering from migraine without aura (female: 45, male: 39; mean age 11.8 ± 2.4 years). According to headache frequency, children/adolescents were divided into two groups: (1) high frequency (patients reporting from weekly to daily attacks), and (2) low frequency (patients having ≤3 episodes per month). We divided headache attacks intensity into two groups (mild and severe pain). SAFA "Anxiety," "Depression," and "Somatization" scales were used to explore children's psychological profile. To evaluate attachment style, the semi-projective test SAT for patients and ASQ Questionnaire for mothers were employed. Maternal alexithymia traits were assessed by TAS-20. Results: We found a significant higher score in maternal alexithymia levels in children classified as "ambivalent," compared to those classified as "avoiding" (Total scale: p = 0.011). A positive correlation has been identified between mother's TAS-20 Total score and the children's SAFA-A Total score (p = 0.026). In particular, positive correlations were found between maternal alexithymia and children's "Separation anxiety" (p = 0.009) and "School anxiety" (p = 0.015) subscales. Maternal "Externally-oriented thinking" subscale correlated with children's school anxiety (p = 0.050). Moreover, we found a correlation between TAS-20 Total score and SAFA-D "Feeling of guilt" subscale (p = 0.014). Our data showed no relationship between TAS-20 and ASQ questionnaires and children's migraine intensity and frequency. Conclusion: Maternal alexithymia and attachment style have no impact on children's migraine severity. However, our results suggest that, although maternal alexithymic traits have no causative roles on children's migraine severity, they show a relationship with patients' attachment style and psychological symptoms, which in turn may impact on migraine severity

Preliminary spacecraft design by means of structured-chromosome genetic algorithms

This paper presents a new methodology for complex system design by means of optimisation techniques. Within the Model-based Engineering approach, optimisation algorithms are used to explore optimal solutions of highly coupled and nonlinear systems. In such scenario, the optimal technology has to be identified and its settings have to be optimised. Relying on optimisation strategies for both the challenges brings to complex mixed-variable problem formulations involving continuous, integer and categorical parameters. Furthermore, part of the parameters are required only if certain technologies are adopted, bringing to variable-size formulations that standard optimisers cannot manage. Therefore, the proposed methodology relies on the use of variable-size mixed-variable global optimiser Structured-Chromosome Genetic Algorithm (SCGA). The advantages of this new method are shown by applying it for solving a space system preliminary design. In particular, two variants have been implemented distinguished by two different levels of complexity. To better appreciate the proposed approach, the same problems have been reformulated to be treated by a well known and appreciated optimiser in the field of spacecraft design, Multi– Population Adaptive Inflationary Differential Evolution Algorithm (MP–AIDEA). The final results of the two approaches are compared and commented

Supporting Team Reflexivity During the COVID-19 Lockdown: A Qualitative Study of Multi-Vision Groups In-Person and Online

Introduction: The professional self is often hindered by a lack of self-care and poor work-life balance, and cannot be considered an unlimited resource. Given this, the reflexive team is an important organizational tool for protecting workers’ well-being. The non-profit organization Maestri di Strada (MdS) (“Street Teachers”) conducts action research (AR) in the area of socio-education. The main tool used by the group to protect the well-being of its members is a guided reflexivity group, inspired by the Balint Group and termed the Multi-Vision Group (MG). In March 2020, because of the COVID-19 lockdown, the MdS team had to quickly revamp its working model, and MGs were held online for the first time. Aim: Through qualitative research that takes a longitudinal approach, the aim of this study is to evaluate the efficacy of the MG in supporting the team’s reflexivity in this new online format. Methods: This article considers MGs during two different time periods: pre-pandemic (T1) and early pandemic (T2). During T1, the MdS team met 18 times in person, while during T2 the team met 12 times through an online platform (always under the guidance of a psychotherapist). During all sessions in both time periods, a silent observer was present in the meetings, and they subsequently compiled narrative reports. The textual corpora of the reports were submitted for a Thematic Analysis of Elementary Contexts through T-Lab Plus, in order to examine the main content of the groups’ discourse. Results: The results (five clusters in T1; and five in T2) show that, during T2, the group devoted considerable time to experiences tied to the pandemic (T21: schools facing the pandemic crisis; T2.2: the pandemic: death, inner worlds, and thought resistance; T2.3: kids’ stories involving physical distancing and emotional proximity). The group also came up with innovative educational initiatives that defied the lockdown (T2.4: fieldwork: the delivery of “packages of food for thought”; T2.5: the MdS group: identity and separation). Based on these findings, the MG most likely contributed to the emergence of MdS as a “resilient community,” capable of absorbing the shock of the pandemic and realizing a fast recovery response

Bioimpedance detection of Oral Lichen Planus used as preneoplastic model

Introduction: Bioimpedance is a measure of the electrical properties of biological tissues. In the last two decades bioimpedance has been successfully introduced in clinical diagnosis of cancer. It has been demonstrated that tumoral tissues often show lower bioimpedance values than healthy tissues. The aim of this work is to assess the bioimpedentiometric differences between healthy and Oral Lichen Planus (OLP) affected oral mucosa, taking attention to the erosive form which may represent a potential pre-cancerous condition. Methods: 52 patients affected by OLP were recruited for bioimpedance examination of oral mucosa. Four electrical properties, resistance (R), reactance (Xc), phase angle (θ) and impedance (Z) of the tongue and of the intraoral mucosa, were measured. Results: We observed a significant increase of Z and a significant decrease of θ values in correspondence of OLP lesions compared to healthy oral mucosa, and a marked decrease of Z values in correspondence of erosive OLP lesions. Conclusions: These results provide evidence of the usefulness of bioimpedance assay for the characterization of healthy and clinically OLP affected mucosa. Bioimpedance is a valid aid in the early detection and clinical monitoring of the suspicious lesions which could lead to a potentially malignant evolution. The present research article is a valuable addition to the scientific literature of cancer prevention, and our findings can be considered extremely encouraging as they represent the initial step for a more wide clinical study for better define the different cut-off values in the different precancerous conditions occurring in the oral mucosa

Assessment and validation of miniaturized technology for the remote tracking of critically endangered Galápagos pink land iguana (Conolophus marthae)

Abstract Background: Gathering ecological data for species of conservation concern inhabiting remote regions can be daunting and, sometimes, logistically infeasible. We built a custom-made GPS tracking device that allows to remotely and accurately collect animal position, environmental, and ecological data, including animal temperature and UVB radiation. We designed the device to track the critically endangered Galápagos pink land iguana, Conolophus marthae. Here we illustrate some technical solutions adopted to respond to challenges associated with such task and present some preliminary results from controlled trial experiments and field implementation. Results: Our tests show that estimates of temperature and UVB radiation are affected by the design of our device, in particular by its casing. The introduced bias, though, is systematic and can be corrected using linear and quadratic regressions on collected values. Our data show that GPS accuracy loss, although introduced by vegetation and orientation of the devices when attached to the animals, is acceptable, leading to an average error gap of less than 15 m in more than 50% of the cases. Conclusions: We address some technical challenges related to the design, construction, and operation of a custommade GPS tracking device to collect data on animals in the wild. Systematic bias introduced by the technological implementation of the device exists. Understanding the nature of the bias is crucial to provide correction models. Although designed to track land iguanas, our device could be used in other circumstances and is particularly useful to track organisms inhabiting locations that are difficult to reach or for which classic telemetry approaches are unattainable

Migraine equivalents and related symptoms, psychological profile and headache features:which relationship?

BACKGROUND: Migraine equivalents are common clinical conditions in children suffering from headache. Very few studies dealt with the psychological profile of children/adolescents with migraine equivalents. Our main aim was to compare the psychological profile between migraine children with and without migraine equivalents. Moreover, as secondary aim, exclusively in children with migraine equivalents, we investigated the possible relationship between migraine attack frequency and intensity and psychological factors. METHODS: We enrolled 136 young migraineurs. They were divided in two groups (patients with and without migraine equivalents). The psychological profile was assessed by means of SAFA Anxiety and Somatization questionnaires. RESULTS: Migraine equivalents were present in 101 patients (74.3 %). Anxiety (p = 0.024) and somatization (p = 0.001) levels, but not hypochondria (p = 0.26), were higher in patients with migraine equivalents. In children with migraine equivalents, a low frequency of attacks was related to separation anxiety (p = 0.034). CONCLUSIONS: Migraine equivalents patients tend to feel more fearful and to experience more shyness. This, together with the tendency to somatization, may lead them to become vigilant in attachment relationships with their caregivers