1,407 research outputs found
Statistical Signs of Social Influence on Suicides
Certain currents in sociology consider society as being composed of
autonomous individuals with independent psychologies. Others, however, deem our
actions as strongly influenced by the accepted standards of social behavior.
The later view was central to the positivist conception of society when in 1887
\'Emile Durkheim published his monograph Suicide (Durkheim, 1897). By treating
the suicide as a social fact, Durkheim envisaged that suicide rates should be
determined by the connections (or the lack of them) between people and society.
Under the same framework, Durkheim considered that crime is bound up with the
fundamental conditions of all social life and serves a social function. In this
sense, and regardless of its extremely deviant nature, crime events are somehow
capable to release certain social tensions and so have a purging effect in
society. The social effect on the occurrence of homicides has been previously
substantiated (Bettencourt et al., 2007; Alves et al., 2013), and confirmed
here, in terms of a superlinear scaling relation: by doubling the population of
a Brazilian city results in an average increment of 135 % in the number of
homicides, rather than the expected isometric increase of 100 %, as found, for
example, for the mortality due to car crashes. Here we present statistical
signs of the social influence on the suicide occurrence in cities. Differently
from homicides (superlinear) and fatal events in car crashes (isometric), we
find sublinear scaling behavior between the number of suicides and city
population, with allometric power-law exponents, and
, for all cities in Brazil and US, respectively. The fact that
the frequency of suicides is disproportionately small for larger cities reveals
a surprisingly beneficial aspect of living and interacting in larger and more
complex social networks.Comment: 7 pages, 4 figure
Non-Local Product Rules for Percolation
Despite original claims of a first-order transition in the product rule model
proposed by Achlioptas et al. [Science 323, 1453 (2009)], recent studies
indicate that this percolation model, in fact, displays a continuous
transition. The distinctive scaling properties of the model at criticality,
however, strongly suggest that it should belong to a different universality
class than ordinary percolation. Here we introduce a generalization of the
product rule that reveals the effect of non-locality on the critical behavior
of the percolation process. Precisely, pairs of unoccupied bonds are chosen
according to a probability that decays as a power-law of their Manhattan
distance, and only that bond connecting clusters whose product of their sizes
is the smallest, becomes occupied. Interestingly, our results for
two-dimensional lattices at criticality shows that the power-law exponent of
the product rule has a significant influence on the finite-size scaling
exponents for the spanning cluster, the conducting backbone, and the cutting
bonds of the system. In all three cases, we observe a continuous variation from
ordinary to (non-local) explosive percolation exponents.Comment: 5 pages, 4 figure
Transport on exploding percolation clusters
We propose a simple generalization of the explosive percolation process
[Achlioptas et al., Science 323, 1453 (2009)], and investigate its structural
and transport properties. In this model, at each step, a set of q unoccupied
bonds is randomly chosen. Each of these bonds is then associated with a weight
given by the product of the cluster sizes that they would potentially connect,
and only that bond among the q-set which has the smallest weight becomes
occupied. Our results indicate that, at criticality, all finite-size scaling
exponents for the spanning cluster, the conducting backbone, the cutting bonds,
and the global conductance of the system, change continuously and significantly
with q. Surprisingly, we also observe that systems with intermediate values of
q display the worst conductive performance. This is explained by the strong
inhibition of loops in the spanning cluster, resulting in a substantially
smaller associated conducting backbone.Comment: 4 pages, 4 figure
Programa para a estimativa do custo e produção de energia eléctrica para uma residência
Este trabalho apresenta um programa de computador que permite determinar o custo e a produção de energia proporcionada por abastecimento pela empresa fornecedora de energia eléctrica e por instalações fotovoltaicas, eólicas e híbridas (fotovoltaicas e eólicas), em função da localização da instalação em território lusitano. Este programa leva em consideração a economia efectuada e o prazo de amortização do investimento. O programa foi realizado com a utilização das seguintes linguagens de programação: HTML, JavaScript e PHP. Pretende-se disponibilizar o uso deste programa através da Internet, para que a sua utilização possa ser alargada ao máximo número de pessoas possível.Fundação para a Ciência e a Tecnologia (FCT), financiadora com fundos FEDER e OE do Projecto POCTI/ESE/48242/2002
Synthesis of 2,6-bis-(oxazolyl)pyridine ligands for luminescent Ln(III) complexes
Submitted to the European Journal of Organic ChemistryNew bis-(oxazolyl)pyridine ligands for Ln(III) ions were prepared using a expeditious methodology from threonine and dipicolinic acid chloride. The synthetic strategy includes a dehydration step to give a bis-dehydroaminobutyric acid derivative followed by bromination and cyclization with DBU. Photophysical studies of Eu(III) and Tb(III) complexes of these ligands showed that the 2,6-bis-(oxazolyl)pyridine moiety acts as an effective sensitizer for lanthanide luminescence and indicate the formation of 3:1 complexes [Ln-(bis-(oxazole)pyridine)3]3+.Fundação para a Ciência e Tecnologia (FCT), QREN, FEDER/E
Towards a genome-wide transcriptogram: the Saccharomyces cerevisiae case
A genome modular classification that associates cellular processes to modules could lead to a method to quantify the differences in gene expression levels in different cellular stages or conditions: the transcriptogram, a powerful tool for assessing cell performance, would be at hand. Here we present a computational method to order genes on a line that clusters strongly interacting genes, defining functional modules associated with gene ontology terms. The starting point is a list of genes and a matrix specifying their interactions, available at large gene interaction databases. Considering the Saccharomyces cerevisiae genome we produced a succession of plots of gene transcription levels for a fermentation process. These plots discriminate the fermentation stage the cell is going through and may be regarded as the first versions of a transcriptogram. This method is useful for extracting information from cell stimuli/responses experiments, and may be applied with diagnostic purposes to different organisms
2D cloud template matching - a comparison between iterative closest point and perfect match
Self-localization of mobile robots in the environment is one of the most fundamental problems in the robotics field. It is a complex and challenging problem due to the high requirements of autonomous mobile vehicles, particularly with regard to algorithms accuracy, robustness and computational efficiency. In this paper we present the comparison of two of the most used map-matching algorithm, which are the Iterative Closest Point and the Perfect Match. This category of algorithms are normally applied in localization based on natural landmarks. They were compared using an extensive collection of metrics, such as accuracy, computational efficiency, convergence speed, maximum admissible initialization error and robustness to outliers in the robots sensors data. The test results were performed in both simulated and real world environments.info:eu-repo/semantics/publishedVersio
Cardiac Troponin T and Illness Severity in the Very-Low-Birth-Weight Infant
Introduction. Respiratory distress are very common in Very-low-birth-weight (VLBW) infants and Myocardial injury may play a role in the disease outcome. Cardiac troponin T (cTnT) is the most useful marker of injury in adult population, but has not been extensively studied in this population. Aim. To study the role of cTnT in VLBW infants and its association with clinical outcomes. Methods. All VLBW infants admitted to our NICU were included in the study. Echocardiography and blood samples for cTnT determination were collected at 24 and 48 hours of life, and values >0.1 ng/mL were considered CTnT-positive values. Results. A total of 116 neonates had their blood samples collected. The median cTnT concentration within 24 hours was 0.191 (0.1–0.79) ng/mL and within 48 hours was 0.293 (0.1–1.0) ng/mL. A logistic regression analysis showed that PDA, low GA, and use of dopamine were independently associated with positive cTnT and abnormal Dopplerfluxometry and diuretics use had protective effects and was independently associated with troponin values. Conclusion. We observed a high prevalence of positivecTnT values in VLBW infants associated with illness severity. Our findings suggest that cTnT may be a useful and early marker of myocardial injury in VLBW infants
Random networks with q-exponential degree distribution
We use the configuration model to generate networks having a degree
distribution that follows a -exponential,
, for arbitrary values of the
parameters and . We study the assortativity and the shortest path
of these networks finding that the more the distribution resembles a pure power
law, the less well connected are the corresponding nodes. In fact, the average
degree of a nearest neighbor grows monotonically with . Moreover,
our results show that -exponential networks are more robust against random
failures and against malicious attacks than standard scale-free networks.
Indeed, the critical fraction of removed nodes grows logarithmically with
for malicious attacks. An analysis of the -core
decomposition shows that -exponential networks have a highest -core,
that is bigger and has a larger than pure scale-free networks. Being at
the same time well connected and robust, networks with -exponential degree
distribution exhibit scale-free and small-world properties, making them a
particularly suitable model for application in several systems.Comment: 6 pages, 8 figure
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