Scaling limit for a drainage network model

We consider the two dimensional version of a drainage network model introduced by Gangopadhyay, Roy and Sarkar, and show that the appropriately rescaled family of its paths converges in distribution to the Brownian web. We do so by verifying the convergence criteria proposed by Fontes, Isopi, Newman and Ravishankar.Comment: 15 page

Regularity at infinity of real mappings and a Morse-Sard theorem

We prove a new Morse-Sard type theorem for the asymptotic critical values of semi-algebraic mappings and a new fibration theorem at infinity for $C^2$ mappings. We show the equivalence of three different types of regularity conditions which have been used in the literature in order to control the asymptotic behaviour of mappings. The central role of our picture is played by the $t$-regularity and its bridge toward the $\rho$-regularity which implies topological triviality at infinity

Infecções parasitárias de híbridos tambatinga (Colossoma macropomum x Piaractus brachypomus) cultivados em pisciculturas de Macapá, Estado do Amapá.

Resumo simples

Axion Like Particles and the Inverse Seesaw Mechanism

Light pseudoscalars known as axion like particles (ALPs) may be behind physical phenomena like the Universe transparency to ultra-energetic photons, the soft $\gamma$-ray excess from the Coma cluster, and the 3.5 keV line. We explore the connection of these particles with the inverse seesaw (ISS) mechanism for neutrino mass generation. We propose a very restrictive setting where the scalar field hosting the ALP is also responsible for generating the ISS mass scales through its vacuum expectation value on gravity induced nonrenormalizable operators. A discrete gauge symmetry protects the theory from the appearance of overly strong gravitational effects and discrete anomaly cancellation imposes strong constraints on the order of the group. The anomalous U$(1)$ symmetry leading to the ALP is an extended lepton number and the protective discrete symmetry can be always chosen as a subgroup of a combination of the lepton number and the baryon number.Comment: 29pp. v4: published version with erratum. Conclusions unchange

Parasitic infections in tambaqui from eight fish farms in Northern Brazil.

The aim of this study was to evaluate the parasites and parasite-host relationship in Colossoma macropomum from eight fish farms in Amapá State, Northern Brazil. A total of 12,242,559 parasites were recovered from hosts in the eight fish farms, and 87.4% of fish were infected by one or more parasite species, such as Ichthyophthirius multifiliis, Piscinoodinium pillulare, Trichodina sp. and Tetrahymena sp. (Protozoa), Anacanthorus spathulatus, Linguadactyloides brinkmanni, Mymarothecium boegeri and Notozothecium janauachensis (Monogenoidea), Procamallanus (Spirocamallanus) inopinatus (Nematoda) and Perulernaea gamitanae and Braga patagonica (Crustacea). Ichthyophthirius multifiliis presented dominance, but the greatest levels of parasitism were caused by I. multifiliis, P. pilulare, monogenoideans species and P. gamitanae, and all these parasites had an aggregate dispersion. The eight fish farms have differences in the parasitic infection levels, management and water quality, which are further discussed here

Generation of higher derivatives operators and electromagnetic wave propagation in a Lorentz-violation scenario

We study the perturbative generation of higher-derivative operators as corrections to the photon effective action, which are originated from a Lorentz violation background. Such corrections are obtained, at one-loop order, through the proper-time method, using the zeta function regularization. We focus over the lowest order corrections and investigate their influence in the propagation of electromagnetic waves through the vacuum, in the presence of a strong, constant magnetic field. This is a setting of experimental relevance, since it bases active efforts to measure non linear electromagnetic effects. After surprising cancellations of Lorentz violating corrections to the Maxwell's equation, we show that no effects of the kind of Lorentz violation we consider can be detected in such a context.Comment: v2: 13 pages, no figures, section IV considerably rewritten, main results unchanged and are now obtained in a simpler way. To appear in PL

Electrochemical aptasensor array for multiple detection of human osteopontin

Electrochemical aptasensor arrays have been recently used to detect several proteins reported as disease biomarkers, mainly due to their known advantages, that include high affinity, sensitivity, specificity and low costs, among others. This study describes the development of a label-free electrochemical multi-aptasensor array, for the simultaneous detection of human osteopontin (OPN), using two specific aptamers. To enable multiplexed protein assay, RNA and DNA aptamers were immobilized in the dual-screen-printed gold working electrodes via streptavidin-biotin interaction, and using the [Fe(CN)6]3-/4- as the redox probe for cyclic voltammetry measurements. The multi-aptasensor array herein developed exhibited a good response and selectivity to detect human OPN in the presence of other interfering proteins. Considering these preliminary results, the DNA/RNA dual aptasensor array could potentially be used as an analytical tool for the specific detection of human OPN, and for cancer diagnosis overall. © 2018, Sociedade Portuguesa de Electroquimica.The authors acknowledge the financial support from the Strategic funding of UID/BIO/04469/2013 and from project ref. RECI/BBB-EBI/ 0179/2012 (project number FCOMP-01-0124-FEDER-027462). This work was also financially supported by Project POCI-01–0145-FEDER-006984 – Associate Laboratory LSRE-LCM and by Project UID/QUI/00616/2013 – CQ-VR, both funded by FEDER - Fundo Europeu de Desenvolvimento Regional through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI) – and by national funds through FCT - Fundação para a Ciência e a Tecnologia, Portugal. S. Meirinho also acknowledges the doctoral grant (ref SFRH/BD/65021/2009) funded by FCT.info:eu-repo/semantics/publishedVersio

Parasitismo em tambatinga (Colossoma macropomum x Piaractus brachypomus, Characidae) cultivados na Amazônia, Brasil.

Os estudos sobre os parasitos e doenças parasitárias são de grande interesse para a piscicultura, uma vez que podem afetar o crescimento dos peixes. O objetivo deste estudo foi investigar a fauna parasitária e relação parasito-hospedeiro em Colossoma macropomumx Piaractus brachypomus(tambatinga) de 10 pisciculturas do estado do Amapá, Amazônia. Dos 503 peixes examinados, 63,1% estavam parasitados e 49.299.189 parasitos foram coletados, tais como Ichthyophthirius multifiliis, Piscinoodinium pillulare, Trichodinasp., Tetrahymenasp., Anacanthorus spathulatus, Linguadactyloides brinkmanni, Mymarothecium boegeri, Notozothecium janauachensis, Procamallanus (Spirocamallanus)inopinatus, Neoechinorhynchus buttneraee Perulernaea gamitanae. Porém, a dominância foi de I. multifiliis, seguida de P. pillularee monogenoideas, parasitos que apresentaram padrão de dispersão agregado juntamente com P. gamitanae. Houve correlação positiva do comprimento dos hospedeiros com a prevalência parasitária total, bem como do tamanho dos peixes com a abundância de I. multiliis, P. pillulare, monogenoideas e P. gamitanae, mas os níveis infecção não influenciaram o fator de condição relativo dos hospedeiros. A ocorrência de ectoparasitos foi favorecida pelo manejo e pobre condição sanitária das pisciculturas, mas a presença de espécies de endoparasitos foi devido ao abastecimento dos viveiros com água provenientes de corpos de água naturais. Este foi primeiro relato de I. multiliis, P. pillulare, Trichodinasp., Tetrahymenasp., A. spathulatus, N. janauachensis, N. buttneraee P.(S.) inopinatus para tambatinga no Brasil