Two Acheuleans, two humankinds. From 1.5 to 0.85 Ma at Melka Kunture (Upper Awash, Ethiopian highlands)

The Acheulean is the longest-lasting human cultural record, spanning approximately 1.5 Ma and three continents. The most comprehensive sequences are found in East Africa, where, in large-scale syntheses, the Lower Pleistocene Acheulean (LPA) has often been considered a uniform cultural entity. Furthermore, the emergence and development of Acheulean technology are seen as linked to the emergence and evolution of Homo ergaster/erectus. The criterion for grouping together different lithic assemblages scattered over space and time is the presence of large cutting tools (LCTs), more than of any other component. Their degree of refinement has been used, in turn, as a parameter for evaluating Acheulean development and variability. But was the East African LPA really uniform as regards all components involved in lithic productions? The aim of this paper is to evaluate the techno-economic similarities and differences among LPA productions in a specific micro-regional and environmental context, i.e. at Melka Kunture, in the Ethiopian highlands, and in a specific period of time: between ~1.5 Ma, when some of the earliest Acheulean complexes appeared, and 1.0-0.85 Ma, when LCTs productions became intensive and widespread. Our detailed comparative analyses investigate all aspects and phases of the chaînes opératoires. Since hominin fossil remains were discovered at some of the analyzed sites, we also discuss differences among lithic productions in relation to the changing paleoanthropological record. Our studies show that at Melka Kunture the LPA techno-complexes cannot be grouped into a single uniform entity. The assembled evidence points instead to “two Acheuleans” well-defined by a strong discontinuity in various aspects of techno-economic behaviors. This discontinuity is related to a major step in human evolution: the transition from Homo ergaster/erectus to Homo heidelbergensis

The unknown Oldowan. ~1.7-million-year-old standardized obsidian small tools from Garba IV, Melka Kunture, Ethiopia

The Oldowan Industrial Complex has long been thought to have been static, with limited internal variability, embracing techno-complexes essentially focused on small-to-medium flake production. The flakes were rarely modified by retouch to produce small tools, which do not show any standardized pattern. Usually, the manufacture of small standardized tools has been interpreted as a more complex behavior emerging with the Acheulean technology. Here we report on the ~1.7 Ma Oldowan assemblages from Garba IVE-F at Melka Kunture in the Ethiopian highland. This industry is structured by technical criteria shared by the other East African Oldowan assemblages. However, there is also evidence of a specific technical process never recorded before, i.e. the systematic production of standardized small pointed tools strictly linked to the obsidian exploitation. Standardization and raw material selection in the manufacture of small tools disappear at Melka Kunture during the Lower Pleistocene Acheulean. This proves that 1) the emergence of a certain degree of standardization in toolkits does not reflect in itself a major step in cultural evolution; and that 2) the Oldowan knappers, when driven by functional needs and supported by a highly suitable raw material, were occasionally able to develop specific technical solutions. The small tool production at ~1.7 Ma, at a time when the Acheulean was already emerging elsewhere in East Africa, adds to the growing amount of evidence of Oldowan techno-economic variability and flexibility, further challenging the view that early stone knapping was static over hundreds of thousands of years

Information measures and cognitive limits in multilayer navigation

Cities and their transportation systems become increasingly complex and multimodal as they grow, and it is natural to wonder if it is possible to quantitatively characterize our difficulty to navigate in them and whether such navigation exceeds our cognitive limits. A transition between different searching strategies for navigating in metropolitan maps has been observed for large, complex metropolitan networks. This evidence suggests the existence of another limit associated to the cognitive overload and caused by large amounts of information to process. In this light, we analyzed the world's 15 largest metropolitan networks and estimated the information limit for determining a trip in a transportation system to be on the order of 8 bits. Similar to the "Dunbar number," which represents a limit to the size of an individual's friendship circle, our cognitive limit suggests that maps should not consist of more than about $250$ connections points to be easily readable. We also show that including connections with other transportation modes dramatically increases the information needed to navigate in multilayer transportation networks: in large cities such as New York, Paris, and Tokyo, more than $80\%$ of trips are above the 8-bit limit. Multimodal transportation systems in large cities have thus already exceeded human cognitive limits and consequently the traditional view of navigation in cities has to be revised substantially.Comment: 16 pages+9 pages of supplementary materia

Entropic measures of individual mobility patterns

Understanding human mobility from a microscopic point of view may represent a fundamental breakthrough for the development of a statistical physics for cognitive systems and it can shed light on the applicability of macroscopic statistical laws for social systems. Even if the complexity of individual behaviors prevents a true microscopic approach, the introduction of mesoscopic models allows the study of the dynamical properties for the non-stationary states of the considered system. We propose to compute various entropy measures of the individual mobility patterns obtained from GPS data that record the movements of private vehicles in the Florence district, in order to point out new features of human mobility related to the use of time and space and to define the dynamical properties of a stochastic model that could generate similar patterns. Moreover, we can relate the predictability properties of human mobility to the distribution of time passed between two successive trips. Our analysis suggests the existence of a hierarchical structure in the mobility patterns which divides the performed activities into three different categories, according to the time cost, with different information contents. We show that a Markov process defined by using the individual mobility network is not able to reproduce this hierarchy, which seems the consequence of different strategies in the activity choice. Our results could contribute to the development of governance policies for a sustainable mobility in modern cities

A stochastic model of randomly accelerated walkers for human mobility

The recent availability of large databases allows to study macroscopic properties of many complex systems. However, inferring a model from a fit of empirical data without any knowledge of the dynamics might lead to erroneous interpretations [6]. We illustrate this in the case of human mobility [1-3] and foraging human patterns [4] where empirical long-tailed distributions of jump sizes have been associated to scale-free super-diffusive random walks called L\'evy flights [5]. Here, we introduce a new class of accelerated random walks where the velocity changes due to acceleration kicks at random times, which combined with a peaked distribution of travel times [7], displays a jump length distribution that could easily be misinterpreted as a truncated power law, but that is not governed by large fluctuations. This stochastic model allows us to explain empirical observations about the movements of 780,000 private vehicles in Italy, and more generally, to get a deeper quantitative understanding of human mobility.Comment: 10 pages, 6 figures + Supplementary informatio

Statistical Laws in Urban Mobility from microscopic GPS data in the area of Florence

The application of Statistical Physics to social systems is mainly related to the search for macroscopic laws, that can be derived from experimental data averaged in time or space,assuming the system in a steady state. One of the major goals would be to find a connection between the statistical laws to the microscopic properties: for example to understand the nature of the microscopic interactions or to point out the existence of interaction networks. The probability theory suggests the existence of few classes of stationary distributions in the thermodynamics limit, so that the question is if a statistical physics approach could be able to enroll the complex nature of the social systems. We have analyzed a large GPS data base for single vehicle mobility in the Florence urban area, obtaining statistical laws for path lengths, for activity downtimes and for activity degrees. We show also that simple generic assumptions on the microscopic behavior could explain the existence of stationary macroscopic laws, with an universal function describing the distribution. Our conclusion is that understanding the system complexity requires dynamical data-base for the microscopic evolution, that allow to solve both small space and time scales in order to study the transients.Comment: 17 pages, 14 figures .jpg, use imsart.cl

Consumo de ração lactação por leitões na maternidade

TCC (graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Agrárias. Curso de Zootecnia.A disponibilização de dietas pré-mater para leitões em fase de aleitamento é importante para ajudar no desenvolvimento do sistema digestivo do animal para que consiga digerir a dieta sólida oferecida a partir do desmame. Porém, alguns leitões apresentam o consumo de ração lactação da porca que, além de possuir nível nutricional diferente do necessitado, contém ingredientes não toleráveis por filhotes. Com o objetivo de avaliar a idade em que começam a consumir e o desempenho de leitões que consomem ração lactação, observou-se 47 leitegadas durante os momentos de alimentação das matrizes, realizando-se pesagens ao nascer, aos cinco dias, aos dez dias de idade e ao desmame. Leitões mais pesados aos dez dias de vida permaneceram mais pesados na data da desmama, assim como os mais leves ao nascer. A idade média de início do consumo de ração da porca foi aos 14 dias. A idade em que começa a comer a ração lactação não interfere no desenvolvimento do animal

Anatomy and efficiency of urban multimodal mobility

International audienceThe growth of transportation networks and their increasing interconnections, although positive,has the downside effect of an increasing complexity which make them difficult to use, to assess, andlimits their efficiency. On average in the UK, 23% of travel time is lost in connections for trips withmore than one mode, and the lack of synchronization decreases very slowly with population size.This lack of synchronization between modes induces differences between the theoretical quickest tripand the ‘time-respecting’ path, which takes into account waiting times at interconnection nodes.We analyse here the statistics of these paths on the multilayer, temporal network of the entire,multimodal british public transportation system. We propose a statistical decomposition – the‘anatomy’ – of trips in urban areas, in terms of riding, waiting and walking times, and which showshow the temporal structure of trips varies with distance and allows us to compare different cities.Weaknesses in systems can be either insufficient transportation speed or service frequency, but thekey parameter controlling their global efficiency is the total number of stop events per hour for allmodes. This analysis suggests the need for better optimization strategies, adapted to short, longunimodal or multimodal trips

Effectiveness of dismantling strategies on moderated vs. unmoderated online social platforms

Online social networks are the perfect test bed to better understand large-scale human behavior in interacting contexts. Although they are broadly used and studied, little is known about how their terms of service and posting rules affect the way users interact and information spreads. Acknowledging the relation between network connectivity and functionality, we compare the robustness of two different online social platforms, Twitter and Gab, with respect to dismantling strategies based on the recursive censor of users characterized by social prominence (degree) or intensity of inflammatory content (sentiment). We find that the moderated (Twitter) vs unmoderated (Gab) character of the network is not a discriminating factor for intervention effectiveness. We find, however, that more complex strategies based upon the combination of topological and content features may be effective for network dismantling. Our results provide useful indications to design better strategies for countervailing the production and dissemination of anti-social content in online social platforms

The Individual 'We' Narrator

The prevailing assumption in literary studies tends to be that a ‘we’ narrative voice is either that of an individual purporting to speak for a group, or that of a collective of people whose perspectives have coalesced into a unified one. Recent work on social agency across the cognitive humanities suggests another way of understanding what might be conveyed by such a ‘we’. Social cognition research shows that individuals can have their capacities changed and enhanced when they interact with others, and suggests that ‘we-representations’ in the individual mind may result from the transformative effects of interaction. In this paper, we draw on a specific instance of storytelling in the plural, William Faulkner’s ‘A Rose for Emily’, to articulate a theory of this ‘individual we’, and to show its potential in refining our understanding of ‘we’ narratives. We also propose that in future research the interdisciplinary study of the ‘we’ could engage with insights from literature as well as from philosophy and science