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openaire: EC/H2020/871042/EU//SoBigData-PlusPlus In an earlier study one of us had developed a model of influence spreading for analysing human behaviour and interaction with others in a social network. Here we apply this model and corresponding influence centrality measures to real data of mobile phone call detail records. From this we get structures of human ego-centric networks and use a simple model, based on the number of phone calls, to describe the strengths of social relationships. To analyse 48,000 egos in their ego-centric networks we define normalised out-centrality and in-centrality influence measures, by dividing with out-degree and in-degree, respectively. With these and the betweenness centrality measures, we analyse the influence spreading in the ego-centric networks under different scenarios of link strengths between individuals reflecting the network structure being either interaction or connectivity oriented. The model reveals characteristics of social behaviour that are not obvious from the data analysis of raw empirical data or from theresults of standard centrality measures. A transition is discovered in behaviour from young to older age groups for both genders and in both normalised out-centrality and in-centrality as well as betweenness centrality results.

Human behaviour follows a 24-h rhythm and is known to be governed by the individual chronotypes. Due to the widespread use of technology in our daily lives, it is possible to record the activities of individuals through their different digital traces. In the present study we utilise a large mobile phone communication dataset containing time stamps of calls and text messages to study the circadian rhythms of anonymous users in a European country. After removing the effect of the synchronization of East-West sun progression with the calling activity, we used two closely related approaches to heuristically compute the chronotypes of the individuals in the dataset, to identify them as morning persons or “larks” and evening persons or “owls”. Using the computed chronotypes we showed how the chronotype is largely dependent on age with younger cohorts being more likely to be owls than older cohorts. Moreover, our analysis showed how on average females have distinctly different chronotypes from males. Younger females are more larkish than males while older females are more owlish. Finally, we also studied the period of low calling activity for each of the users which is considered as a marker of their sleep period during the night. We found that while “extreme larks” tend to sleep more than “extreme owls” on the weekends, we do not observe much variation between them on weekdays. In addition, we have observed that women tend to sleep even less than males on weekdays while there is not much difference between them on the weekends.

Using large-scale call detail records of anonymised mobile phone service subscribers with demographic and location information, we investigate how a long-distance residential move within the country affects the mobile communication patterns between an ego who moved and a frequently called alter who did not move. By using clustering methods in analysing the call frequency time series, we find that such ego-alter pairs are grouped into two clusters, those with the call frequency increasing and those with the call frequency decreasing after the move of the ego. This indicates that such residential moves are correlated with a change in the communication pattern soon after moving. We find that the pre-move calling behaviour is a relevant predictor for the post-move calling behaviour. While demographic and location information can help in predicting whether the call frequency will rise or decay, they are not relevant in predicting the actual call frequency volume. We also note that at four months after the move, most of these close pairs maintain contact, even if the call frequency is decreased., published version in EPJ Data Science

Background: Acute subdural hematoma (aSDH) in the elderly is an increasingly important public health issue. Mortality rate in this population can be as high as 90% (Copper et al., 1976; Cagetti et al., 1992; Taussky et al., 2012; Hanif, 2009; Raj et al., 2016; Luerssen et al., 1988). Objective: The goal of this study is to examine outcomes for patients 70 years and older who underwent craniotomy for aSDH. Methods: This is a retrospective study of patients 70 years and older who underwent craniotomy for evacuation of aSDH between 2006 and 2016. Patients with subacute, chronic, acute-on-chronic SDH and those considered too neurologically devastated to benefit from surgery were excluded. A multivariable logistic regression was performed to identify independent clinical factors associated with mortality. Results: A total of 1953 elderly patients with SDH were seen between 2006 and 2016. 1325 patients had non-surgical SDH, 307 were too neurologically devastated to benefit from surgery, and 321 elderly patients had surgery. 112 patients had a craniotomy for aSDH. The overall mortality rate was 42%. 24% of patients were discharged to home or a rehabilitation facility. Multivariable logistic regression analysis showed that age, Glasgow Coma Scale (GCS) score, and surgery type had a significant impact on mortality. Conclusion: Elderly patients with aSDH requiring surgery have a high likelihood of mortality. 24% of surgical patients were functional enough to go home or to a rehabilitation facility from the hospital. Age over 80 years old, GCS

Coordination and cooperation between humans and autonomous agents in cooperative games raises interesting questions of human decision making and behaviour changes. Here we report our findings from a group formation game in a small-world network of different mixes of human and agent players, aiming to achieve connected clusters of the same colour by swapping places with neighbouring players using non-overlapping information. In the experiments the human players are incentivized by rewarding to prioritize their own cluster while the model of agents' decision making is derived from our previous experiment of purely cooperative game between human players. The experiments were performed by grouping the players in three different setups to investigate the overall effect of having cooperative autonomous agents within teams. We observe that the change in the behavior of human subjects adjusts to playing with autonomous agents by being less risk averse, while keeping the overall performance efficient by splitting the behaviour into selfish and cooperative in the two actions performed during the rounds of the game. Moreover, results from two hybrid human-agent setups suggest that the group composition affects the evolution of clusters. Our findings indicate that in purely or lesser cooperative settings, providing more control to humans could help in maximizing the overall performance of hybrid systems., Chosen to be published in Scientific Reports on 24.05.2021 with DOI: 10.1038/s41598-021-90123-8

Human behaviour follows a 24-hour rhythm and is known to be governed by the individual chronotypes. Due to the widespread use of technology in our daily lives, it is possible to record the activities of individuals through their different digital traces. In the present study we utilise a large mobile phone communication dataset containing time stamps of calls and text messages to study the circadian rhythms of anonymous users in a European country. After removing the effect of the synchronization of East-West sun progression with the calling activity, we used two closely related approaches to heuristically compute the chronotypes of the individuals in the dataset, to identify them as morning persons or “larks” and evening persons or “owls”. Using the computed chronotyes we showed how the chronotype is largely dependent on age with younger cohorts being more likely to be owls than older cohorts. Moreover, our analysis showed how on average females have distinctly different chronotypes from males. Younger females are more larkish than males while older females are more owlish. Finally, we also studied the period of low calling activity for each of the users which is considered as a marker of their sleep period during the night. We found that while “extreme larks” tend to sleep more than “extreme owls” on the weekends, we do not observe much variation between them on weekdays. In addition, we have observed that women tend to sleep even less than males on weekdays while there is not much difference between them on the weekends.

We investigate the dynamics of regular fractal-like networks of hierarchically coupled van der Pol oscillators. The hierarchy is imposed in terms of the coupling strengths or link weights. We study the low frequency modes, as well as frequency and phase synchronization, in the network by a process of repeated coarse-graining of oscillator units. At any given stage of this process, we sum over the signals from the oscillator units of a clique to obtain a new oscillating unit. The frequencies and the phases for the coarse-grained oscillators are found to progressively synchronize with the number of coarse-graining steps. Furthermore, the characteristic frequency is found to decrease and finally stabilize to a value that can be tuned via the parameters of the system. We compare our numerical results with those of an approximate analytic solution and find good qualitative agreement. Our study on this idealized model shows how oscillations with a precise frequency can be obtained in systems with heterogeneous couplings. It also demonstrates the effect of imposing a hierarchy in terms of link weights instead of one that is solely topological, where the connectivity between oscillators would be the determining factor, as is usually the case. Many oscillatory signaling processes in nature are multi-scale, where the characteristic macro-scale frequency of the signal is an emergent property of the coupling of oscillators of different frequencies acting on the micro-scale. Here, we show, using a combination of numerical simulations and analytical investigations, how oscillations of a precise frequency can be obtained from a fractal network of oscillators when the coupling is heterogeneous. Our results on various hierarchically coupled networks shed light on how the frequencies synchronize and the phases become locked at various scales. Our model also shows how the concept of hierarchy can be realized when studying synchronization in weighted networks.

We present a link-centric approach to study variation in the mobile phone communication patterns of individuals. Unlike most previous research on call detail records that focused on the variation of phone usage across individual users, we examine how the calling and texting patterns obtained from call detail records vary among pairs of users and how these patterns are affected by the nature of relationships between users. To demonstrate this link-centric perspective, we extract factors that contribute to the variation in the mobile phone communication patterns and predict demographics-related quantities for pairs of users. The time of day and the channel of communication (calls or texts) are found to explain most of the variance among pairs that frequently call each other. Furthermore, we find that this variation can be used to predict the relationship between the pairs of users, as inferred from their age and gender, as well as the age of the younger user in a pair. From the classifier performance across different age and gender groups as well as the inherent class overlap suggested by the estimate of the bounds of the Bayes error, we gain insights into the similarity and differences of communication patterns across different relationships.

We study the influence of seasonally and geographically related daily dynamics of daylight and ambient temperature on human resting or sleeping patterns using mobile phone data of a large number of individuals. We observe two daily inactivity periods in the people's aggregated mobile phone calling patterns and infer these to represent the resting times of the population. We find that the nocturnal resting period is strongly influenced by the length of daylight, and that its seasonal variation depends on the latitude, such that for people living in two different cities separated by eight latitudinal degrees, the difference in the resting period of people between the summer and winter in southern cities is almost twice that in the northern cities. We also observe that the duration of the afternoon resting period is influenced by the temperature, and that there is a threshold from which this influence sets in. Finally, we observe that the yearly dynamics of the afternoon and nocturnal resting periods appear to be counterbalancing each other. This also lends support to the notion that the total daily resting time of people is more or less conserved across the year., This version substitutes the previous manuscript (with old title "Seasonal and geographical influence on sleeping patterns inferred from mobile phone data"), which now is split into two manuscripts due to its length and new investigations added. The current version includes the part related to seasonal variations of the resting periods

We analyze a large-scale mobile phone call dataset containing information on the age, gender, and billing locality of users to get insight into social closeness in pairs of individuals of similar age. We show that in addition to using the demographic information, the ranking of contacts by their call frequency in egocentric networks is crucial to characterize the different communication patterns. We find that mutually top-ranked opposite-gender pairs show the highest levels of call frequency and daily regularity, which is consistent with the behavior of real-life romantic partners. At somewhat lower level of call frequency and daily regularity come the mutually top-ranked same-gender pairs, while the lowest call frequency and daily regularity are observed for mutually non-top-ranked pairs. We have also observed that older pairs tend to call less frequently and less regularly than younger pairs, while the average call durations exhibit a more complex dependence on age. We expect that a more detailed analysis can help us better characterize the nature of relationships between pairs of individuals and distinguish between various types of relations, such as siblings, friends, and romantic partners., 17 pages, 5 figures, 2 tables. Journal of Computational Social Science (published online, 2019)

Background Cost-effectiveness analyses for the treatment of aneurysmal subarachnoid hemorrhage are necessary to determine health policy, treatment guidelines, and screening protocols for cerebral aneurysms. To perform these modeling studies, detailed cost data are necessary and are currently lacking. Objective The goal of this study was to determine detailed inpatient cost of aneurysmal subarachnoid hemorrhage. Methods A retrospective review of our ruptured subarachnoid hemorrhage database was performed to identify consecutive patients between January 2013 and December 2015. Patients were searched by International Classification of Disease 9 diagnosis and procedure codes. Patient demographics and clinical characteristics were acquired. The cost breakdown was compiled into a comprehensive itemized list encompassing all aspects of hospitalization. A mean cost based on resource used per patient was obtained. Results There were 269 patients treated, 209 were coiled and 60 were clipped. Mean age in the clipping group was 49 years and 55 years in the coil group (P = 0.006). Other patient demographics and clinical characteristics were found to be statistically similar for both groups. Total cost per patient for treatment and hospital stay was $74,192 for clipping and $85,553 for coiling (P = 0.06). Cost amplified with increasing Hunt and Hess grade in both clipping and coiling groups. Conclusions The detailed cost information reported in this article can be used to help establish appropriate, standardized costs nationally by improving transparency. It can also help provide critical information necessary to develop cost-effective treatment algorithms and screening protocols.

As a step towards studying human-agent collectives we conduct an online game with human participants cooperating on a network. The game is presented in the context of achieving group formation through local coordination. The players set initially to a small world network with limited information on the location of other players, coordinate their movements to arrange themselves into groups. To understand the decision making process we construct a data-driven model of agents based on probability matching. The model allows us to gather insight into the nature and degree of rationality employed by the human players. By varying the parameters in agent based simulations we are able to benchmark the human behaviour. We observe that while the players utilize the neighbourhood information in limited capacity, the perception of risk is optimal. We also find that for certain parameter ranges the agents are able to act more efficiently when compared to the human players. This approach would allow us to simulate the collective dynamics in games with agents having varying strategies playing alongside human proxies., Comment: 23 pages, 9 figures

In this brief review, we discuss some recent findings of human sociality in contemporary techno-social networks of interacting individuals. Here we will focus on a few important observations obtained by analysing mobile communication data of millions of users in a European country participating in billions of calls and text messages over a period of one year. In addition to the description of the basic structure of the network in terms of its topological characteristics like the degree distribution or the clustering coefficient, the demographic information of the users have been utilized to get deeper insight into the various facets of human sociality related to age and gender as reflected in the communication patterns of users. One of the observations suggests that the grandmothering effect is clearly visible in these communication patterns. In addition it is found that the number of friends or connections of a user show a clear decaying trend as a function of the user’s age for both genders. Furthermore, an analysis of the most common location of the users shows the effect of distance on close relationships. As computational analysis and modelling are the two key approaches or tools of modern ‘Social Physics’ we will very briefly discuss the construction of a social network model to get insight into how plausible microscopic social interaction processes translate to meso- and macroscopic socially weighted network structures between individuals.

Social networks require active relationship maintenance if they are to be kept at a constant level of emotional closeness. For primates, including humans, failure to interact leads inexorably to a decline in relationship quality, and a consequent loss of the benefits that derive from individual relationships. As a result, many social species compensate for weakened relationships by investing more heavily in them. Here we study how humans behave in similar situations, using data from mobile call detail records from a European country. For the less frequent contacts between pairs of communicating individuals we observe a logarithmic dependence of the duration of the succeeding call on the time gap with the previous call. We find that such behaviour is likely when the individuals in these dyadic pairs have the same gender and are in the same age bracket as well as being geographically distant. Our results indicate that these pairs deliberately invest more time in communication so as to reinforce their social bonding and prevent their relationships decaying when these are threatened by lack of interaction., 16 pages, 11 figures (Supplementary Material included)

Using a large dataset with individual-level demographic information of 60,000 families in contemporary Finland, we analyse the variation and cultural assortativity in a network of families. Families are considered as vertices and unions between males and females who have a common child and belong to different families are considered as edges in such a network of families. The sampled network is a collection of many disjoint components with the largest connected component being dominated by families rooted in one specific region. We characterize the network in terms of the basic structural properties and then explore the network transitivity and assortativity with regards to regions of origin and linguistic identity. Transitivity is seen to result from linguistic homophily in the network. Overall, our results demonstrate that geographic proximity and language strongly influence the structuring of network., Comment: 25 pages, 12 figures

openaire: EC/H2020/662725/EU//IBSEN Age and gender are two important factors that play crucial roles in the way organisms allocate their social effort. In this study, we analyse a large mobile phone dataset to explore the way life history influences human sociality and the way social networks are structured. Our results indicate that these aspects of human behaviour are strongly related to age and gender such that younger individuals have more contacts and, among them, males more than females. However, the rate of decrease in the number of contacts with age differs between males and females, such that there is a reversal in the number of contacts around the late 30s. We suggest that this pattern can be attributed to the difference in reproductive investments that are made by the two sexes. We analyse the inequality in social investment patterns and suggest that the age- and genderrelated differences we find reflect the constraints imposed by reproduction in a context where time (a form of social capital) is limited.

Neuropathic pain is a chronic condition lacking effective management and responding poorly to standard treatment protocols. Motor cortex stimulation has emerged as a new and promising therapeutic tool with outcomes potentially affected by the specific causes and location. In this study we report a series of eight cases in the neurosurgery practice of one of the authors (R.J.B.), including neuropathic pain syndromes of trigeminal or thalamic origin with or without anesthesia dolorosa. Pain relief was evaluated on the basis of comparison of Visual Analog scores at baseline and at 3 months after surgery. In addition, we assessed differences in pain relief outcomes between cases with trigeminal neuralgia and thalamic stroke, as well as cases with or without anesthesia dolorosa (i.e. pain with numbness of the affected area). Visual Analog Scale scores showed a statistically significant decrease of 4.19 (P=0.002) at 3 months follow-up compared with baseline. Pain relief levels in four of five patients in the subgroup with facial pain were higher than 50%, and none of the patients in the subgroup with thalamic and phantom limb pain showed such a good outcome. Furthermore, we found larger pain relief levels in facial pain conditions with versus without anesthesia dolorosa. These results point to utility of motor cortex stimulation in relieving neuropathic pain, as well as better outcomes for patients with facial pain and anesthesia dolorosa. Future studies should incorporate methods to noninvasively trial those patients who may benefit from surgical implantation to predict the outcomes and maximize their negative predictive value.

Aneurysmal subarachnoid hemorrhage (SAH) is the most devastating form of hemorrhagic stroke. Primary predictors of mortality are based on initial clinical presentation. Initial serum lactic acid levels have been shown to predict mortality and disease severity. Initial serum lactate may be an objective predictor or mortality.Retrospective review of aneurysmal SAH in a large academic center over a 42-month period. Data collected included demographics, clinical data, serum, and clinical outcomes data. Epidemiologic data were collected at baseline, and patients were followed up through their inpatient stay. We compared data in the group of patients who were deceased (group A) vs survivors (group B).There were a total of 249 patients. Mortality was 21.5%. Mean age was the same for both groups: 57 years (group A) and 55 years (group B). Mean admission serum lactate level was 3.5 ± 2.5 (group A) and 2.2 ± 1.6 (group B; P. 0001). The range was 0.01 to 14.7. Multivariable analysis controlling for Hunt and Hess grades showed lactic acid levels to be an independent predictor of mortality with a P value of .0018.In aneurysmal SAH, elevated serum lactate levels on admission may have a predictive role for mortality and represent a marker of disease severity. Currently, lactic acid levels are not ordered on all patients with SAH but perhaps should be part of the routine initial blood work and may serve as an additional prognostic marker.

Each stage of the human life course is characterized by a distinctive pattern of social relations. We study how the intensity and importance of the closest social contacts vary across the life course, using a large database of mobile communication from a European country. We first determine the most likely social relationship type from these mobile phone records by relating the age and gender of the caller and recipient to the frequency, length, and direction of calls. We then show how communication patterns between parents and children, romantic partner, and friends vary across the six main stages of the adult family life course. Young adulthood is dominated by a gradual shift of call activity from parents to close friends, and then to a romantic partner, culminating in the period of early family formation during which the focus is on the romantic partner. During middle adulthood call patterns suggest a high dependence on the parents of the ego, who, presumably often provide alloparental care, while at this stage female same-gender friendship also peaks. During post-reproductive adulthood, individuals and especially women balance close social contacts among three generations. The age of grandparenthood brings the children entering adulthood and family formation into the focus, and is associated with a realignment of close social contacts especially among women, while the old age is dominated by dependence on their children., Comment: 20 pages, 5 figures

Timings of human activities are marked by circadian clocks which in turn are entrained to different environmental signals. In an urban environment the presence of artificial lighting and various social cues tend to disrupt the natural entrainment with the sunlight. However, it is not completely understood to what extent this is the case. Here we exploit the large-scale data analysis techniques to study the mobile phone calling activity of people in large cities to infer the dynamics of urban daily rhythms. From the calling patterns of about 1,000,000 users spread over different cities but lying inside the same time-zone, we show that the onset and termination of the calling activity synchronizes with the east-west progression of the sun. We also find that the onset and termination of the calling activity of users follows a yearly dynamics, varying across seasons, and that its timings are entrained to solar midnight. Furthermore, we show that the average mid-sleep time of people living in urban areas depends on the age and gender of each cohort as a result of biological and social factors., Author summary For humans living in urban areas, the modern daily life is very different from that of people who lived in ancient times, from which todays’ societies evolved. Mainly due to the availability of artificial lighting, modern humans have been able to modify their natural daily cycles. In addition, social rules, like those related to work and schooling, tend to require specific schedules for the daily activities. However, it is not fully understood to what extent the seasonal changes in sunrise and sunset times and the length of daylight could influence the timings of these activities. In this study, we use a new approach to describe the dynamics of human resting periods in terms of mobile phone calling activity, showing that the onset and termination of the resting pattern of urban humans follow the east-west sun progression inside the same timezone. Also we find that the onset of the low calling activity period as well as its mid-time, are subjected to seasonal changes, following the same dynamics as solar midnight. Moreover, with resting time measured as the low activity periods of people in cities, we discover significant behavioural differences between different age and gender cohorts. These findings suggest that the length and timings of the human daily rhythms, still have a sensitive dependence on the seasonal changes of the sunlight.

En este trabajo se estudia un modelo de flujo bifásico (agua-aceite) en un medio poroso homogéneo considerando un desplazamiento inmiscible e incompresible. Este modelo se resuelve numéricamente usando el Método de Volumen Finito (FVM) y se comparan cuatro esquemas numéricos para la aproximación de los flujos en las caras de los volúmenes discretos. Se describe brevemente cómo obtener los modelos matemático y computacional aplicando la formulación axiomática y programación genérica. También, implementa dos estrategias de paralelización para reducir el tiempo de ejecución. Se utilizan arquitecturas de memoria distribuida (clusters de CPUs) y memoria compartida (Tar- jetas gráficas GPUs). Finalmente se realiza una comparación del desempeño de estas dos arquitecturas junto con un análisis de los cuatro esquemas numéricos para un patrón de flujo de inyección de agua, con un pozo inyector y cuatro pozos productores (five-spot pattern).

The concept of "building block" has played an important role in science and also at a more formal level in the notion of search, especially in the context of Evolutionary Computation. However, there is still a great deal that is not understood about why, or even if, building blocks help in search. In this paper we introduce an elementary search problem and a class of search algorithms that use building blocks. We consider how the use of building blocks affects the efficiency of the search and moreover how the characteristics of the building blocks - the number of types and their sizes - greatly influences the search.