Consistent patterns of common species across tropical tree communities

Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees

J/psi production as a function of charged-particle pseudorapidity density in p-Pb collisions at root s(NN)=5.02 TeV

We report measurements of the inclusive J/ψ yield and average transverse momentum as a function of charged-particle pseudorapidity density dNch/dη in p–Pb collisions at sNN=5.02TeV with ALICE at the LHC. The observables are normalised to their corresponding averages in non-single diffractive events. An increase of the normalised J/ψ yield with normalised dNch/dη, measured at mid-rapidity, is observed at mid-rapidity and backward rapidity. At forward rapidity, a saturation of the relative yield is observed for high charged-particle multiplicities. The normalised average transverse momentum at forward and backward rapidities increases with multiplicity at low multiplicities and saturates beyond moderate multiplicities. In addition, the forward-to-backward nuclear modification factor ratio is also reported, showing an increasing suppression of J/ψ production at forward rapidity with respect to backward rapidity for increasing charged-particle multiplicity

Intraoperative topical administration of mitomycin C, in different concentrations, on the cicatrization of mioplasties of the dorsal rectus of rabbits Administração tópica per-operatória da mitomicina C, em diferentes concentrações, sobre a cicatrização de mioplastias do reto dorsal de coelhos

Myoplasties of the extraocular muscle may cause adhesions between the operated muscle and the adjacent tissues, commonly generating cicatricial strabismus. With the purpose of reducing to a minimum the occurrence of adhesion, the effects of mitomycin C, an antifibrotic agent, were studied in concentrations of 0.008%, 0.02%, and 0.04% applied during intraoperative of myoplasties of the superior rectus muscle of rabbits. Fifty six animals were divided in five groups. During the postoperative, the operated areas were washed with physiological solution. Eye drop instillation to prevent inflammation and bacterial infection were used. The method to analyze the results consisted of clinical and histological evaluation and statistical analyzes. We also evaluated at the same time the amount of basic fibroblast growth factor (FGF-2) by immunohistochemical study. Clinically, more adhesions were found in the eyes of the control group than in the groups of treated eyes. However there was no significant statistics difference between the two groups (P>0.05). Histologically, mitomycin C caused a delayed cicatrization in the mioplastic areas, specially in the group who received the 0.02% concentration. The immunohistochemical showed FGF-2 marking in fibroblasts and macrophages, but between the groups there wasn't no difference. Based on those results, mitomycin C in the utilized concentrations was capable of delaying the cicatrization and consequently avoid the secondary strabismus without undesirable side effects.<br>Mioplastias da musculatura extra-ocular podem ensejar aderências entre o músculo operado e os tecidos adjacentes, produzindo, não raro, estrabismos cicatriciais. Com intuito de se minimizar a ocorrência de aderências, investigaram-se os efeitos da mitomicina C, como agente antifibrótico, em concentrações ascendentes de 0,008, 0,02 e 0,04%, aplicada no per-operatório de mioplastias do reto superior do bulbo do olho de coelhos. Operaram-se 56 animais, que compuseram cinco grupos. No pós-operatório, instituíram-se limpeza com solução fisiológica das áreas operadas e profilaxia antimicrobiana e antiinflamatória, na forma de colírio. Avaliações clínica, histológica e imunoistoquímica, em que se estudou o fator de crescimento fibroblástico-básico (FGF-2), e estatística compuseram os métodos de análise dos resultados. Encontraram-se, clinicamente, mais aderências nos olhos-controle, comparativamente aos tratados, embora sem diferença estatística (P>0,05). À histologia, verificou-se que a mitomicina C ensejou retardo da cicatrização junto às áreas das mioplastias, notadamente no grupo que a recebeu, à concentração de 0,02%. A imunoistoquímica revelou marcação do FGF-2 em fibroblastos e macrófagos indistintamente entre os grupos. Com base nos resultados, permite-se admitir que a mitomicina C, nas concentrações em que foi empregada, retardou a cicatrização e, por conseguinte, o estrabismo secundário, sem ensejar efeitos colaterais

Enhanced production of multi-strange hadrons in high-multiplicity proton-proton collisions

At sufficiently high temperature and energy density, nuclear matter undergoes a transition to a phase in which quarks and gluons are not confined: the quark-gluon plasma (QGP). Such an exotic state of strongly interacting quantum chromodynamics matter is produced in the laboratory in heavy nuclei high-energy collisions, where an enhanced production of strange hadrons is observed. Strangeness enhancement, originally proposed as a signature of QGP formation in nuclear collisions, is more pronounced for multi-strange baryons. Several effects typical of heavy-ion phenomenology have been observed in high-multiplicity proton-proton (pp) collisions, but the enhanced production of multi-strange particles has not been reported so far. Here we present the first observation of strangeness enhancement in high-multiplicity proton-proton collisions. We find that the integrated yields of strange and multi-strange particles, relative to pions, increases significantly with the event charged-particle multiplicity. The measurements are in remarkable agreement with the p-Pb collision results, indicating that the phenomenon is related to the final system created in the collision. In high-multiplicity events strangeness production reaches values similar to those observed in Pb-Pb collisions, where a QGP is formed. © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved