Effects of mobility in a population of prisoner's dilemma players

We address the problem of how the survival of cooperation in a social system depends on the motion of the individuals. Specifically, we study a model in which prisoner's dilemma players are allowed to move in a two-dimensional plane. Our results show that cooperation can survive in such a system provided that both the temptation to defect and the velocity at which agents move are not too high. Moreover, we show that when these conditions are fulfilled, the only asymptotic state of the system is that in which all players are cooperators. Our results might have implications for the design of cooperative strategies in motion coordination and other applications including wireless networks.

Stability of synchronization in simplicial complexes

Various systems in physics, biology, social sciences and engineering have been successfully modeled as networks of coupled dynamical systems, where the links describe pairwise interactions. This is, however, too strong a limitation, as recent studies have revealed that higher-order many-body interactions are present in social groups, ecosystems and in the human brain, and they actually affect the emergent dynamics of all these systems. Here, we introduce a general framework to study coupled dynamical systems accounting for the precise microscopic structure of their interactions at any possible order. We show that complete synchronization exists as an invariant solution, and give the necessary condition for it to be observed as a stable state. Moreover, in some relevant instances, such a necessary condition takes the form of a Master Stability Function. This generalizes the existing results valid for pairwise interactions to the case of complex systems with the most general possible architecture.

Remote synchronization in star networks

We study phase synchronization in a network motif with a starlike structure in which the central node's (the hub's) frequency is strongly detuned against the other peripheral nodes. We find numerically and experimentally a regime of remote synchronization (RS), where the peripheral nodes form a phase synchronized cluster, while the hub remains free with its own dynamics and serves just as a transmitter for the other nodes. We explain the mechanism for this RS by the existence of a free amplitude and also show that systems with a fixed or constant amplitude, such as the classic Kuramoto phase oscillator, are not able to generate this phenomenon. Further, we derive an analytic expression which supports our explanation of the mechanism.

Forgetting what you have checked: a link between working memory impairment and checking behaviors in obsessive-compulsive disorder

BACKGROUND

Compulsive checking behaviors are common in obsessive-compulsive disorder (OCD). Several authors have suggested that these checking rituals could be related to memory deficits. Our aim was to test whether patients with OCD show working memory impairment in relation to their checking behavior.

METHODS

We evaluated the verbal and visuospatial components of patients' and controls' working memory using the reading span and backward location span tests. Checking behaviors were measured by recording participants' eye movements during an image comparison task using a non-invasive, infra-red TOBII 1750 eyetracker. Participants were seated, head-free, in a natural position in front of the eyetracker screen where the images were displayed.

RESULTS

Patients with OCD made more gaze moves to compare images than controls. Both patients' working memory spans were reduced, and the patients' deficit in the comparison task was negatively related to their working memory spans.

CONCLUSIONS

This work demonstrates that checking behavior in OCD is linked to a general reduction of the patients' verbal and visuospatial working memory span.

Support practices by an interdisciplinary team in a palliative-care unit for relatives of patients in agonal phase

Background

In the absence of extant recommendations, the aim of this study was to formalise support practices used by an interdisciplinary team in a palliative-care unit (PCU) for the relatives of patients in the agonal phase preceding death. The secondary objective was to understand the expectations of relatives during this phase in terms of the support provided by professionals and volunteers.

Methods

Thirty-two people took part in this study; all were interviewed through focus groups (FGs). Each FG comprised one category of individuals working in the PCU: nurses, care- assistants, doctors, psychologists, other professionals, palliative-care volunteers, and relatives. Groups were surveyed using an interview guide, and the interviews were recorded and transcribed to enable identification and characterization of all practices. Care practices were classified into four categories: current consensual practices (i.e. performed by all team members), occasional consensual practices, non-consensual practices (performed by one or a few participants), and practices to be developed.

Results

In total, 215 practices were mentioned by professionals and palliative-care volunteers: 150 current consensual practices, 48 occasional consensual practices, 1 non-consensual practice, 16 practices yet to be developed, and 29 practices for relatives. Many practices were mentioned by different categories of participants; thus, after cross-checking, the number of practices decreased from 215 to 52. A list of practices deemed desirable by all was drawn up and then validated by the entire interprofessional team. These practices were organised around four themes: providing care and ensuring comfort; communicating, informing, and explaining; interacting; and mobilising interdisciplinary skills.

Conclusions

These results underline the importance of the quality of care provided to patients, the attention given to the relatives themselves, and they highlight the importance of the helping relationship. Following this study, which established a list of varied practices aimed at supporting the relatives of patients in agonal phase, it will be important to set up a broader study seeking to establish a consensus on these practices with an interprofessional group of experts from other PCUs using broad surveys and an adapted methodology. Such studies will make it possible to develop training modules for teams working with relatives.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12904-020-00680-4.

Direct measurement of electrostriction in optical fibers

The electrostriction contribution to the nonlinear refractive index in optical fiber was theoretically calculated and measured. Nonlinearity was induced directly by insertion of the optical fiber into an intense external electric field. With this technique both the Kerr and the electrostrictive contributions to the intensity dependence of the nonlinear refractive index in a step-index fiber were measured. Good agreement between calculated and measured values was observed. These results should confirm and explain the differences observed in measurement of n(2) at different bit rates.

AIDS related information, attitudes and behaviours among Italian male young people

In order to evaluate the AIDS related sources of information, knowledge, attitudes and behaviours among male young people it was filled in a multi-choice anonymous questionnaire by 2018 subjects, called for the first medical examination to Italian Navy and by 1348 recruits. The data from the latter group were used to make comparisons with our previous survey carried out in 1988. The most important sources of information on AIDS were mass media and school, on sexuality friends and family. AIDS awareness was greater among the high educated subjects and positively influenced by mass media and school as sources of information. In agreement with these data, knowledge was better about AIDS than about sexuality. Risk perception was positively influenced by the AIDS-related knowledge for called youth and a greater intolerance towards infected people was observed among the less educated and the less AIDS-aware subjects. On average 46% of the called up young men and 74% of recruits declared to be sexually active: among these, the mean age at the first sexual intercourse was 16, over 60% declared to have had multiple partners, over 30% unknown partners and over 30% didn't use condoms; 20% of called up and 38% of recruits indicated 2 or 3 risk behaviours. Factors determining sex-related risks were different according to the behaviour and the considered group. These results suggest that it is important for young people to be well informed about sex and AIDS before the beginning of sexual activity, if possible during compulsory school.

[Antibacterial effect of Nd:YAG laser in periodontal pockets decontamination: a in vivo study]

AIM

Tha aim of this paper is to assess the effects in vivo of the Nd: Yag laser on gingival microflora in patients periodontally at risk.

METHODS

An investigation has been carried out on 5 patients suffering from serious periodontal disease, with a sub-gingival check-up a week after the treatment. The selected patients presented either a relapse after the raising of a traditional flap, or showed acute phenomena and were, therefore, treated with a laser with the propedeutic intention of surgery; or they refused traditional surgical therapy or presented systematic pathologies that could not be included in the appropriate protocol. Pockets were chosen that had a probe depth of between 5-8 mm, an optic fibre probe was pushed as far as possible into the probe depth, for about 1 minute per site, 5 times, at 30 second intervals. The samples, taken in order to calculate bacteria colonies, were carried out before using the laser, immediately after and, again, 1 week later.

RESULTS

All the sites showed a slight reduction in the quantity of colonies forming immediately after the Nd:Yag laser application, while a week later, only if clinical inflammation appeared to be resolved, the bacteria forming colonies seemed to be reduced.

CONCLUSION

From this study it can be concluded that the use of the Nd:Yad laser represents, in mild and average periodontitis, a therapeutic aid to scaling and root planing and, in the same way, in serious periodontitis for traditional surgical therapy.

A nonlinear circuit architecture for magnetoencephalographic signal analysis

OBJECTIVES

The objective of this paper was to face the complex spatio-temporal dynamics shown by Magnetoencephalography (MEG) data by applying a nonlinear distributed approach for the Blind Sources Separation. The effort was to characterize and differ-entiate the phases of a yogic respiratory exercise used in the treatment of obsessive compulsive disorders.

METHODS

The patient performed a precise respiratory protocol, at one breath per minute for 31 minutes, with 10 minutes resting phase before and after. The two steps of classical Independent Component Approach have been performed by using a Cellular Neural Network with two sets of templates. The choice of the couple of suitable templates has been carried out using genetic algorithm optimization techniques.

RESULTS

Performing BSS with a nonlinear distributed approach, the outputs of the CNN have been compared to the ICA ones. In all the protocol phases, the main components founded with CNN have similar trends compared with that ones obtained with ICA. Moreover, using this distributed approach, a spatial location has been associated to each component.

CONCLUSIONS

To underline the spatio-temporal and the nonlinearly of the neural process a distributed nonlinear architecture has been proposed. This strategy has been designed in order to overcome the hypothesis of linear combination among the sources signals, that is characteristic of the ICA approach, taking advantage of the spatial information.

Recurrence analysis of strange nonchaotic dynamics in driven excitable systems

Numerous studies have shown that strange nonchaotic attractors (SNAs) can be observed generally in quasiperiodically forced systems. These systems could be one- or high-dimensional maps, continuous-time systems, or experimental models. Recently introduced measures of complexity based on recurrence plots can detect the transitions from quasiperiodic to chaotic motion via SNAs in the previously cited systems. We study here the case of continuous-time systems and experimental models. In particular, we show the performance of the recurrence measures in detecting transitions to SNAs in quasiperiodically forced excitable systems and experimental time series.

Palliative care delivery according to age among metastatic breast cancer patients. ESME-MBC cohort

Background

Metastatic breast cancer (MBC) may require inpatient palliative care (IPC) but literature suggests age-related disparities in palliative care delivery. This study, based on real-world data, aimed to assess the cumulative incidence function (CIF) of IPC delivery and if age is an independent factor, taking into account the competing risk of death.

Methods

The national multicenter ESME (Epidemio-Strategy-Medical-Economical)-MBC cohort includes consecutive MBC patients treated in the 18 French Comprehensive Cancer Centers. IPC identification used ICD-10 palliative care coding. Main analysis first estimated pseudo values of 2-year and 8-year CIF of IPC. Linear regression models estimated the mean changes of pseudo-values (2 models: 2-year and 8-year CIF of IPC).

Results

Our analysis included 12375 patients, 5093 (41.2%) of whom were aged 65 or over. The median follow-up was 41.5 months (95% CI, 40.5-42.5). The CIF of IPC was 10.3% (95% CI, 10.2-10.4) and 24.8% (95% CI, 24.7-24.8) at two and eight years, respectively. At two years, among triple-negative patients, young patients (<65 yo) had a higher CIF of IPC than older patients after adjusting for cancer characteristics, centre, and period (65+/<65: β=-0.05; 95% CI, -0.08 to -0.01). Among other tumour subtypes, older patients received short-term IPC more frequently than young patients (65+/<65: β = 0.02; 95% CI, 0.01 to 0.03). At eight years, outside large centres, IPC was delivered less frequently to older patients adjusted to cancer characteristics and period (65+/<65: β=-0.03; 95% CI, -0.06 to -0.01).

Conclusions

We found a relatively low CIF of IPC and that age influenced IPC delivery. Young triple negative and older non-triple negative patients needed more short-term IPC. Older patients diagnosed outside large centres received less long-term IPC. These findings highlight the need for a wider implementation of IPC facilities and for more age-specific interventions.

Key messages

Our study highlighted particular challenge for older MBC patients diagnosed outside large French Comprehensive Cancer Centers. By identifying age at MBC diagnosis as a factor of IPC delivery, this report supports a wider implementation of IPC facilities and more age-specific interventions.

Genetic dissection of crossover mutants defines discrete intermediates in mouse meiosis

Crossovers (COs), the exchange of homolog arms, are required for accurate chromosome segregation during meiosis. Studies in yeast have described the single-end invasion (SEI) intermediate: a stabilized 3' end annealed with the homolog as the first detectible CO precursor. SEIs are thought to differentiate into double Holliday junctions (dHJs) that are resolved by MutLgamma (MLH1/MLH3) into COs. Currently, we lack knowledge of early steps of mammalian CO recombination or how intermediates are differentiated in any organism. Using comprehensive analysis of recombination in thirteen different genetic conditions with varying levels of compromised CO resolution, we infer CO precursors include asymmetric SEI-like intermediates and dHJs in mouse. In contrast to yeast, MLH3 is structurally required to differentiate CO precursors into dHJs. We verify conservation of aspects of meiotic recombination and show unique features in mouse, providing mechanistic insight into CO formation.

A programmable electronic circuit for modelling CO2 laser dynamics

We introduce a programmable electronic circuit implementing the rich dynamics of CO2 laser models. The design and the implementation of the circuit are accomplished by using a programmable analog device, which permits an experimental characterization of the laser dynamics. The experimental results shown in the paper demonstrate that the circuit exhibits homoclinic chaos typical of CO2 laser with feedback modulation of cavity losses. Moreover, experimental results showing that noise regularizes the dynamical time scales of the system are reported.

Efficacy of an emollient dermoprotective cream in the treatment of elderly skin affected by xerosis

AIM

Xerosis cutis is a frequent condition in the elderly and the topical treatments are aimed to maintain a balance between the physiological components of the epidermis and an optimal moisturization. The aim was to evaluate the efficacy of a dermoprotective cream, glycerol and paraffin-based, in the treatment of individuals affected by senile xerosis.

METHODS

The patients were recruited at the Professional Dermatology and Allergology Outpatient Clinic of the San Gallicano Dermatological Institute of Rome, between 1st January 2013 and 30th September 2014. To assess the efficacy of the cream, two different areas of treatment were identified in each patient upper the limbs. All patients were staged at baseline (T0) and evaluated after 14 days (T1) and 28 days (T2) of topical treatment, using five clinical parameters: scaling, sensation of skin tightness, presence of fissuring and excoriations from scratching and erythema. The itching degree was also evaluated using a 10-steps analogical scale.

RESULTS

Fifty patients with xerosis, 25 with a severe and 25 with a moderate form, over 60 were recruited and evaluated. Median age was 65 years (IQR=61-70). After 28 day of topical administration of the cream, the 54.0% of patients showed the absence of signs of xerosis, the 44.0% a mild form and the 2.0% (one patient) a moderate form. Consistently, a progressive and significative reduction of itching and transepidermal water loss (TEWL), and an improvement in skin hydration was also measured. A good profile of tolerability and no episodes of undesirable side effects, was also observed.

CONCLUSION

The topical daily use of a cream glycerol and paraffin-based, seem to able to control the xerosis in elderly patients, with a significant reduction of all associated signs and symptoms. Further additional data should be collected to better confirm the role of the topical treatment in the control of disease.

[Infections in heart transplantations]

Infections are one of the most important problems in heart transplants recipients: they are responsible for half total mortality within one year after surgery and one third of mortality during the following period. Underlying medical illness of the host, lack of specific immunity, prior colonization are conditions that may contribute to infections after surgery: immunosuppression to contrast rejection or due to Cytomegalovirus (CMV) infection are other factors favoring infections. Lung infections are most frequent. During the first month after surgery microorganisms responsible are the same found in cardiosurgery patients, staphylococci and gram negative, and occasionally herpes simplex virus (ESV) reactivated infections occur. From the second to the sixth month most of the CMV and Toxoplasma infections occur, with some Pneumocystis and mycotic events. Both are so frequent that in a seronegative host a specific prophylaxis against CMV and Toxoplasma is regularly recommended. The very late period more than six month after surgery is characterized by common infections seen in any population, that may present in altered or more severe fashion due to immune suppression. Another late event is cryptococcal meningitis.