Scaling laws and universality in the choice of election candidates

Nowadays there is an increasing interest of physicists in finding regularities related to social phenomena. This interest is clearly motivated by applications that a statistical mechanical description of the human behavior may have in our society. By using this framework, we address this work to cover an open question related to elections: the choice of elections candidates (candidature process). Our analysis reveals that, apart from the social motivations, this system displays features of traditional out-of-equilibrium physical phenomena such as scale-free statistics and universality. Basically, we found a non-linear (power law) mean correspondence between the number of candidates and the size of the electorate (number of voters), and also that this choice has a multiplicative underlying process (lognormal behavior). The universality of our findings is supported by data from 16 elections from 5 countries. In addition, we show that aspects of network scale-free can be connected to this universal behavior.Comment: Accepted for publication in EP

Rhizosphere microbial community composition of common beans with different levels of resistance to Fusarium oxysporum.

Microbial communities in the rhizosphere make significant contributions to plant health, growth and protection against soil pathogens. Plants can take advantage of their rhizosphere microbiomes to fend off pathogens, avoiding microbial infections. Here, we aimed to identify potential microbial groups and functional traits correlated to the suppression of the soil borne Microbial diversity and functioning in the soil ecosystem 145 pathogen Fusarium oxysporum. Through shotgun metagenomics we investigated the rhizosphere microbial communities of four common bean cultivars with different levels of resistance to the fungus, ranging from susceptible to resistant. Plants were grown in mesocosms experiments with two contrasting soils, i.e. Amazon Dark Earth (ADE) and an agricultural soil (AS). The soils presented clear differences in chemical properties, and ADE hosts higher microbial diversity than AS. Chemical analysis indicated a significant increase of pH, Ca, Fe, sum of bases and base saturation, and decrease of K, Mg, exchangeable Al, and Mn in rhizosphere of both soil types. Quantitative PCR showed an increase of 16S rRNA copy number with the increase resistance to the fungus in ADE soil. The rhizosphere of the four bean cultivars is dominated by the same bacterial phyla Proteobacteria, Actinobacteria, Firmicutes, and Chloroflexi, albeit in different relative abundance between soil types. The community structure of rhizosphere was different from the bulk soil, revealing the selection process in this environment. In ADE soil, the most resistant cultivar presented higher taxonomic diversity when compared to other cultivars; in contrast, the functional diversity was lower. Comparing the resistant to the susceptible cultivars there was an increase of Nitrospirae, Solibacteres, Spirochaeta and Chryosiogenetes bacterial classes in the resistant. Also, resistant cultivar presented high number of sequences affiliated to the family Pseudomonadaceae and to the genera Bacillus and Solibacter. Interestingly, the resistant and moderately resistant cultivars, presented high proportion of sequences related to bacteriocin, a narrow spectrum antibiotic, which suggests its role on pathogen suppression. Preliminary analysis showed that the selection of the microbial communities inhabiting the common bean rhizosphere is cultivar and soil type dependent. Further analysis will search for bacterial groups potentially related to the fungal antagonism. FAPESP 2014/03217-3

Analysis of the rhizosphere microbial communities of common beans resistant and susceptible to Fusarium oxysporum.

The rhizosphere is the narrow zone of soil around the living plant roots that is influenced by the activity of the plants. Many beneficial microorganisms in the rhizosphere provide plants with mineral nutrients, phytohormones, and also help to protect the plant against soil-borne pathogens. Microbiological studies are addressed to understand how rhizosphere microorganisms are recruited from soil and either benefit or harm plant growth, nutrition and health. Here, we aimed to identify potential microbial groups and functional traits correlated to the suppression of the soil borne pathogen Fusarium oxysporum, the causal agent of Fusarium wilt on common beans. We used shotgun metagenomics to investigate the rhizosphere microbiome of two common bean cultivars classified as resistant (Milênio) and susceptible (Alvorada). Plants were grown in mesocosms experiments in Amazon Dark Earth, a soil with high microbial diversity. Chemical analysis indicated a significant increase of pH, Ca, Fe, Zn, Mn, B, nitrate, cation exchange capacity, sum of bases and base saturation in rhizosphere of both common bean types. The microbial community structure of rhizosphere was different from the bulk soil in a deeper taxonomic classification (genera), revealing the selection process in this environment. Quantitative PCR showed an increase of 16S rRNA copy number with the increase resistance to the fungus in ADE soil. The resistant cultivar presented higher taxonomic diversity but lower functional diversity. The most abundant phyla in rhizosphere were Proteobacteria (41%), Actinobacteria (31%), Firmicutes (5%), Acidobacteria (3%) and Chloroflexi (3%). The resistant cultivar presented more abundance of the phyla Chlamydiae, Spirochaetes, Deinococcus-Thermus and Chrysiogenetes in comparison to the susceptible one and bulk soil. Comparing the resistant to the susceptible cultivar in a finer taxonomic level, 24 genera presented higher abundance in the resistant one, highlighting Bacillus and Pseudomonas. Preliminary analysis showed that there is a specific selection of the microbial communities inhabiting the rhizosphere of a resistant common bean cultivar. Further analysis will combine 16S rRNA gene sequencing and metatranscriptome for a deep taxonomical and functional analysis

Metagenomic analysis of the rhizosphere microbiome of the common bean resistant to Fusarium oxysporum.

The rhizosphere microbiome plays a key role in the functioning of the host plant, influencing its physiology and development. It has been suggested that plants use mechanisms present in the rhizosphere microbiome to fend off infections, such as fungal diseases. This work aimed to assess the microbial community inhabiting the common bean rhizosphere in order to identify potential groups related to the suppression of the soil-borne pathogen Fusarium oxysporum. Therefore, using shotgun metagenomic sequencing (Illumina Miseq), we investigated the phylogenetic and potential functional diversity of microbial communities colonizing the rhizosphere of four cultivars of common bean with different levels of resistance to the fungus, ranging from high susceptibility to resistant. Quantitative PCR of total bacteria in rhizosphere samples showed in increase of 16S rRNA copy number with the increase of resistance to the fungus. Mesocosms experiments, including four common bean cultivars cultivated in Amazonian Dark Earth and three replicates, were conducted in greenhouse conditions and we obtained over than 12 million metagenomic sequences. The overall microbial diversity did not present significant variations across common bean cultivars. From the classified sequences, 97,4% were affiliated to Bacteria and 1,48% to Archaea. Proteobacteria represented the most abundant phyla (41,7%), followed by Actinobacteria (29,4%), Firmicutes (5,9%) and Acidobacteria (4,1%). The microbial communities structure were different between bulk soil and rhizosphere samples. Comparing all bean cultivars, the resistant one showed an overrepresention of the phyla Spirochaetes, Nitrospirae and Euryarchaeota. The resistant bean cultivar presented high number of sequences affiliated to the genus Bacillus. Interestingly, the resistant and moderately resistant cultivars, presented high proportion of sequences related to bacteriocin, a narrow spectrum antibiotics. Preliminary analysis showed that different common bean cultivars could select differential microbial groups in the rhizosphere environment. Further analysis will search for bacterial groups potentially related to the fungal antagonism

Dirac quantization of a nonminimal gauged O(3) sigma model

The (2+1) dimensional gauged O(3) nonlinear sigma model with Chern-Simons term is canonically quantized. Furthermore, we study a nonminimal coupling in this model implemented by means of a Pauli-type term. It is shown that the set of constraints of the model is modified by the introduction of the Pauli coupling. Moreover, we found that the quantum commutator relations in the nominimal case is independent of the Chern-Simons coefficient, in contrast to the minimal one.Comment: 7 pages, to appear in Modern Physics Letters

Geometry, stochastic calculus and quantum fields in a non-commutative space-time

The algebras of non-relativistic and of classical mechanics are unstable algebraic structures. Their deformation towards stable structures leads, respectively, to relativity and to quantum mechanics. Likewise, the combined relativistic quantum mechanics algebra is also unstable. Its stabilization requires the non-commutativity of the space-time coordinates and the existence of a fundamental length constant. The new relativistic quantum mechanics algebra has important consequences on the geometry of space-time, on quantum stochastic calculus and on the construction of quantum fields. Some of these effects are studied in this paper.Comment: 36 pages Latex, 1 eps figur

The Impact of High Particles Concentration in a Biofuel Droplet Combustion

Aviation is one of the largest transportation sectors and is operated on fossil fuels, being responsible for about 2% of global CO2 emissions. In order to reduce the environmental impact, biofuels emerged as a promising solution. Additionally, a possible approach to improve the performance of biofuels is to add nanoparticles, leading to the concept of nanofuel. The present work evaluates the nanofuel droplet combustion of a biofuel containing high aluminum particle concentrations. To enhance the nanofuel stability, a preliminary study focusing on the addition of a surfactant was mandatory. Particle size of 40 nm and three particle concentrations from 1.0 to 4.0 wt.% were considered. The results show that the oleic acid effectively improves the stability, and no visible oxidation of the nanoparticles was reported. Regarding the single droplet combustion, the observations show that the addition of nanoparticles promotes micro-explosions, contrary to the combustion of pure biofuel, and increases the overall droplet burning rate.Fundação para a Ciência e a Tecnologiainfo:eu-repo/semantics/publishedVersio