Ghost dynamics in the soft gluon limit

We present a detailed study of the dynamics associated with the ghost sector of quenched QCD in the Landau gauge, where the relevant dynamical equations are supplemented with key inputs originating from large-volume lattice simulations. In particular, we solve the coupled system of Schwinger-Dyson equations that governs the evolution of the ghost dressing function and the ghost-gluon vertex, using as input for the gluon propagator lattice data that have been cured from volume and discretization artifacts. In addition, we explore the soft gluon limit of the same system, employing recent lattice data for the three-gluon vertex that enters in one of the diagrams defining the Schwinger-Dyson equation of the ghost-gluon vertex. The results obtained from the numerical treatment of these equations are in excellent agreement with lattice data for the ghost dressing function, once the latter have undergone the appropriate scale-setting and artifact elimination refinements. Moreover, the coincidence observed between the ghost-gluon vertex in general kinematics and in the soft gluon limit reveals an outstanding consistency of physical concepts and computational schemes.Comment: 34 pages, 12 figure

Placentation in Sigmodontinae: a rodent taxon native to South America

Background: Sigmodontinae, known as ""New World rats and mice,"" is a large subfamily of Cricetidae for which we herein provide the first comprehensive investigation of the placenta. Methods: Placentas of various gestational ages ranging from early pregnancy to near term were obtained for five genera, i.e. Necromys, Euryoryzomys, Cerradomys, Hylaeamys, and Oligoryzomys. They were investigated by means of histology, immunohistochemistry, a proliferation marker, DBA-lectin staining and transmission electron microscopy. Results: The chorioallantoic placenta was organized in a labyrinthine zone, spongy zone and decidua and an inverted yolk sac persisted until term. The chorioallantoic placenta was hemotrichorial. The interhemal barrier comprised fetal capillary endothelium and three layers of trophoblast, an outermost, cellular layer and two syncytial ones, with interspersed trophoblast giant cells (TGC). In addition, accumulations of TGC occurred below Reichert's membrane. The junctional zone contained syncytial trophoblast, proliferative cellular trophoblast, glycogen cells and TGC that were situated near to the maternal blood channels. In three of the genera, TGC were also accumulated in distinct areas at the placental periphery. PAS-positive glycogen cells derived from the junctional zone invaded the decidua. Abundant maternal uNK cells with positive response to PAS, vimentin and DBA-lectin were found in the decidua. The visceral yolk sac was completely inverted and villous. Conclusion: The general aspect of the fetal membranes in Sigmodontinae resembled that found in other cricetid rodents. Compared to murid rodents there were larger numbers of giant cells and in some genera these were seen to congregate at the periphery of the placental disk. Glycogen cells were found to invade the decidua but we did not identify trophoblast in the walls of the deeper decidual arteries. In contrast these vessels were surrounded by large numbers of uNK cells. This survey of wild-trapped specimens from five genera is a useful starting point for the study of placentation in an important subfamily of South American rodents. We note, however, that some of these rodents can be captive bred and recommend that future studies focus on the study of time dated pregnancies.This research was supported by grants from FAPESP (Proc. 07/51491-3 and\ud 09/53392-8)

Chorioallantoic and yolk sac placentation in the plains viscacha (Lagostomus maximus) - A caviomorph rodent with natural polyovulation

Objectives: Reproduction in the plains viscacha is characterized by the polyovulation of hundreds of oocytes, the loss of implantation and the development of 1-3 offspring. Our goal was to determine whether placental development was affected by these specializations. Study design: Thirteen placentas from early pregnancy to near-term pregnancy were analyzed using histological, immunohistochemical and transmission electron microscopy. Results: An inverted, villous yolk sac was present. Placentas were formed by the trophospongium, labyrinth and subplacenta. A lobulated structure with a hemomonochorial barrier was established early in pregnancy. Proliferating trophoblast that was clustered at the outer border and inside the labyrinth was responsible for placental growth. Trophoblast invasion resulted from the cellular trophoblast and syncytial streamers derived from the subplacenta. Different from other caviomorphs, numerous giant cells were observed. Conclusions: The principle processes of placentation in caviomorphs follow an extraordinarily stable pattern that is independent of specializations, such as polyovulation.Facultad de Ciencias Veterinaria

Modelo experimental de lesão pulmonar aguda para estudo de manobras de recrutamento alveolar

O artigo não apresenta resumo

Lubricated revolute joints in rigid multibody systems

The main purpose of this work is to present a general methodology for modeling lubricated revolute joints in constrained rigid multibody systems. In the dynamic analysis of journal-bearings, the hydrodynamic forces, which include both squeeze and wedge effects, generated by the lubricant fluid, oppose the journal motion. The hydrodynamic forces are obtained by integrating the pressure distribution evaluated with the aid of Reynolds’ equation, written for the dynamic regime. The hydrodynamic forces built up by the lubricant fluid are evaluated from the system state variables and included into the equations of motion of the multibody system. Numerical examples are presented in order to demonstrate the use of the methodologies and procedures described in this work.Fundação para a Ciência e a Tecnologia (FCT

Chorioallantoic and yolk sac placentation in the plains viscacha (Lagostomus maximus) - A caviomorph rodent with natural polyovulation

Objectives: Reproduction in the plains viscacha is characterized by the polyovulation of hundreds of oocytes, the loss of implantation and the development of 1-3 offspring. Our goal was to determine whether placental development was affected by these specializations. Study design: Thirteen placentas from early pregnancy to near-term pregnancy were analyzed using histological, immunohistochemical and transmission electron microscopy. Results: An inverted, villous yolk sac was present. Placentas were formed by the trophospongium, labyrinth and subplacenta. A lobulated structure with a hemomonochorial barrier was established early in pregnancy. Proliferating trophoblast that was clustered at the outer border and inside the labyrinth was responsible for placental growth. Trophoblast invasion resulted from the cellular trophoblast and syncytial streamers derived from the subplacenta. Different from other caviomorphs, numerous giant cells were observed. Conclusions: The principle processes of placentation in caviomorphs follow an extraordinarily stable pattern that is independent of specializations, such as polyovulation.Facultad de Ciencias Veterinaria

Microglia dysfunction caused by the loss of Rhoa disrupts neuronal physiology and leads to neurodegeneration

© 2020 The Author(s). Creative Commons Attribution (CC BY 4.0)Nervous tissue homeostasis requires the regulation of microglia activity. Using conditional gene targeting in mice, we demonstrate that genetic ablation of the small GTPase Rhoa in adult microglia is sufficient to trigger spontaneous microglia activation, producing a neurological phenotype (including synapse and neuron loss, impairment of long-term potentiation [LTP], formation of β-amyloid plaques, and memory deficits). Mechanistically, loss of Rhoa in microglia triggers Src activation and Src-mediated tumor necrosis factor (TNF) production, leading to excitotoxic glutamate secretion. Inhibiting Src in microglia Rhoa-deficient mice attenuates microglia dysregulation and the ensuing neurological phenotype. We also find that the Rhoa/Src signaling pathway is disrupted in microglia of the APP/PS1 mouse model of Alzheimer disease and that low doses of Aβ oligomers trigger microglia neurotoxic polarization through the disruption of Rhoa-to-Src signaling. Overall, our results indicate that disturbing Rho GTPase signaling in microglia can directly cause neurodegeneration.The authors acknowledge the support of the following i3S Scientific Platforms: Animal Facility, Translational Cytometry Unit (TraCy), BioSciences Screening (BS) and Advanced Light Microscopy (ALM), and members of the national infrastructure PPBI-Portuguese Platform of BioImaging (supported by POCI-01–0145-FEDER-022122). FCT Portugal ( PTDC/MED-NEU/31318/2017-031318 ) supported work in the J.B.R. lab. FCT Portugal , PEst ( UID/NEU/04539/2013 ), COMPETE-FEDER ( POCI-01-0145-FEDER-007440 ), Centro 2020 Regional Operational Programme ( CENTRO-01-0145-FEDER-000008 : BrainHealth 2020), and Strategic Project UIDB/04539/2020 and UIDP/04539/2020 (CIBB) supported work in the A.F.A. lab. C.C.P. and R.S. hold employment contracts financed by national funds through FCT (Fundação para a Ciência e a Tecnologia, I.P.) in the context of the program contract described in paragraphs 4, 5, and 6 of article 23 of law no. 57/2016, of August 29th, as amended by law no. 57/2017 of July 19th.info:eu-repo/semantics/publishedVersio

PATOGENICIDADE DE ESPÉCIES DE Macrophomina COLETADAS DE PLANTAS DANINHAS EM FEIJÃO-CAUPI

[PT] A podridão de carvão causada por Macrophomina phaseolina é uma das principais doenças do feijão-caupi, causando perdas substanciais para os produtores. Na região semiárida do Brasil, o feijão-caupi é uma das alternativas utilizadas para rotação de culturas durante a entressafra do melão. Isso favorece a multiplicação de Macrophomina, uma vez que ambas as culturas são hospedeiras desse patógeno. O objetivo deste estudo foi verificar a patogenicidade em caupi de Macrophomina phaseolina e M. pseudophaseolina em caupi. Isolados de Macrophomina spp. obtidos das raízes de Trianthema portulacastrum e Boerhavia diffusa, espécies de plantas daninhas prevalentes em áreas de produção de melão no Nordeste brasileiro foram utilizadas neste estudo. O experimento foi realizado em casa de vegetação. Plantas de feijão-caupi 'Paulistinha' foram inoculados com 30 isolados de M. phaseolina, 30 isolados de M. pseudophaseolina e um isolado de referência de M. phaseolina obtido de raízes de feijão-caupi. Todos os isolados de Macrophomina foram patogênicos ao feijão-caupi, não havendo diferenças estatísticas entre as duas espécies de Macrophomina em relação à incidência e severidade da doença. Além disso, 65,2 e 100,0% dos isolados de M. phaseolina, e 56,2 e 92,8% dos isolados de M. pseudophaseolina, obtidos de T. portulacastrum e B. diffusa, respectivamente, foram tão severos ao feijão-caupi quanto o isolado de referência. Esses resultados enfatizam a necessidade de estabelecer práticas de manejo visando o controle de T. portucalastrum e B. diffusa nas áreas de produção de feijão-caupi, pois podem atuar como fontes de inóculo e sobrevivência para Macrophomina spp.[EN] Charcoal rot caused by Macrophomina phaseolina is a major cowpea disease causing substantial losses to growers. In the semi-arid region of Brazil, cowpea is one of the most widely used alternatives for crop rotation during the off-season of melon. This favors Macrophomina multiplication because both crops are hosts of this pathogen. The objective of this study was to verify the pathogenicity of Macrophomina phaseolina and M. pseudophaseolina on cowpea. The Macrophomina spp. isolates used were obtained from the roots of Trianthema portulacastrum and Boerhavia diffusa, weed species prevalent in melon production areas in North-east Brazilian The experiment was carried out in a greenhouse. Cowpea plants cv. Paulistinha' were inoculated with 30 M. phaseolina isolates, 30 M. pseudophaseolina isolates and a reference isolate of H. phaseolina obtained from cowpea roots. All Macrophomina isolates were able to cause disease on cowpea and there were no statistical differences between both Macrophomina species regarding disease incidence and severity. Moreover, 65.2 and 100.0% of the M. phaseolina isolates, and 56.2 and 92.8% of the M. pseudophaseolina isolates, obtained from T. portulacastrum and B. diffusa, respectively, were as severe to cowpea as the M. phaseolina reference isolate from cowpea. These results emphasize the need to establish management practices aiming to control T. portucalastrum and B. diffusa from cowpea production areas, as they can act as potential sources of inoculum and survival for Macrophomina spp.This study was partially financed by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior -Brazil (CAPES) -Finance Code 001 and by the Conselho Nacional de desenvolvimento Cientifico e Tecnologico (CNPq).Sales Jr., R.; Nogueira, A.; Mitsa Paiva Negreiros, A.; Rodrigues, T.; De Queiroz, M.; Armengol Fortí, J. (2020). PATHOGENICITY OF Macrophomina SPECIES COLLECTED FROM WEEDS IN COWPEA. Revista Caatinga. 33(2):395-401. https://doi.org/10.1590/1983-21252020v33n212rcS395401332Ambrósio, M. M. Q., Dantas, A. C. A., Martínez-Perez, E., Medeiros, A. C., Nunes, G. H. S., & Picó, M. B. (2015). Screening a variable germplasm collection of Cucumis melo L. for seedling resistance to Macrophomina phaseolina. Euphytica, 206(2), 287-300. doi:10.1007/s10681-015-1452-xFreitas, F. C. L., Medeiros, V. F. L. P., Grangeiro, L. C., Silva, M. G. O., Nascimento, P. G. M. L., & Nunes, G. H. (2009). Interferência de plantas daninhas na cultura do feijão-caupi. Planta Daninha, 27(2), 241-247. doi:10.1590/s0100-83582009000200005Gomes-Silva, F., Almeida, C. M. A., Silva, A. G., Leão, M. P. C., Silva, K. P., Oliveira, L. G., … Lima, V. L. M. (2017). Genetic Diversity of Isolates of Macrophomina phaseolina Associated with Cowpea from Brazil Semi-Arid Region. Journal of Agricultural Science, 9(11), 112. doi:10.5539/jas.v9n11p112Gupta, G. K., Sharma, S. K., & Ramteke, R. (2012). Biology, Epidemiology and Management of the Pathogenic Fungus Macrophomina phaseolina (Tassi) Goid with Special Reference to Charcoal Rot of Soybean (Glycine max (L.) Merrill). Journal of Phytopathology, 160(4), 167-180. doi:10.1111/j.1439-0434.2012.01884.xKaur, S., Dhillon, G. S., Brar, S. K., Vallad, G. E., Chand, R., & Chauhan, V. B. (2012). Emerging phytopathogenMacrophomina phaseolina: biology, economic importance and current diagnostic trends. Critical Reviews in Microbiology, 38(2), 136-151. doi:10.3109/1040841x.2011.640977Machado, A. R., Pinho, D. B., Soares, D. J., Gomes, A. A. M., & Pereira, O. L. (2018). Bayesian analyses of five gene regions reveal a new phylogenetic species of Macrophomina associated with charcoal rot on oilseed crops in Brazil. European Journal of Plant Pathology, 153(1), 89-100. doi:10.1007/s10658-018-1545-1Mbaye, N., Mame, P. S., Ndiaga, C., & Ibrahima, N. (2015). Is the recently described Macrophomina pseudophaseolina pathogenically different from Macrophomina phaseolina? African Journal of Microbiology Research, 9(45), 2232-2238. doi:10.5897/ajmr2015.7742Negreiros, A. M. P., Sales Júnior, R., León, M., Melo, N. J., Michereff, S. J., Ambrósio, M. M., … Armengol, J. (2019). Identification and pathogenicity of Macrophomina species collected from weeds in melon fields in Northeastern Brazil. Journal of Phytopathology, 167(6), 326-337. doi:10.1111/jph.12801Negreiros, A. M. P., Júnior, R. S., Rodrigues, A. P. M. S., León, M., & Armengol, J. (2019). Prevalent weeds collected from cucurbit fields in Northeastern Brazil reveal new species diversity in the genusMonosporascus. Annals of Applied Biology, 174(3), 349-363. doi:10.1111/aab.12493Ramos, H. M. M., Bastos, E. A., Andrade Júnior, A. S. de, & Marouelli, W. A. (2012). Estratégias ótimas de irrigação do feijão‑caupi para produção de grãos verdes. Pesquisa Agropecuária Brasileira, 47(4), 576-583. doi:10.1590/s0100-204x2012000400014Reis, E. M., Boaretto, C., & Danelli, A. L. D. (2014). Macrophomina phaseolina: density and longevity of microsclerotia in soybean root tissues and free on the soil, and competitive saprophytic ability. Summa Phytopathologica, 40(2), 128-133. doi:10.1590/0100-5405/1921Rocha, M. de M., Carvalho, K. J. M. de, Freire Filho, F. R., Lopes, Â. C. de A., Gomes, R. L. F., & Sousa, I. da S. (2009). Controle genético do comprimento do pedúnculo em feijão-caupi. Pesquisa Agropecuária Brasileira, 44(3), 270-275. doi:10.1590/s0100-204x2009000300008Sales Junior, R., Oliveira, O. F. de, Medeiros, É. V. de, Guimarães, I. M., Correia, K. C., & Michereff, S. J. (2012). Ervas daninhas como hospedeiras alternativas de patógenos causadores do colapso do meloeiro. Revista Ciência Agronômica, 43(1), 195-198. doi:10.1590/s1806-66902012000100024Sales Júnior, R., Rodrigues, A. P. M. dos S., Negreiros, A. M. P., Ambrósio, M. M. de Q., Barboza, H. da S., & Beltrán, R. (2019). WEEDS AS POTENTIAL HOSTS FOR FUNGAL ROOT PATHOGENS OF WATERMELON. Revista Caatinga, 32(1), 1-6. doi:10.1590/1983-21252019v32n101rcFrancisco, de A. S. e S., & Carlos, A. V. de A. (2016). The Assistat Software Version 7.7 and its use in the analysis of experimental data. African Journal of Agricultural Research, 11(39), 3733-3740. doi:10.5897/ajar2016.11522Silva, M. G. O. da, Freitas, F. C. L. de, Negreiros, M. Z. de, Mesquita, H. C. de, Santana, F. A. O. de, & Lima, M. F. P. de. (2013). Manejo de plantas daninhas na cultura da melancia nos sistemas de plantio direto e convencional. Horticultura Brasileira, 31(3), 494-499. doi:10.1590/s0102-05362013000300025Zhao, L., Cai, J., He, W., & Zhang, Y. (2019). Macrophomina vaccinii sp. nov. causing blueberry stem blight in China. MycoKeys, 55, 1-14. doi:10.3897/mycokeys.55.3501

Changes in calcium dynamics following the reversal of the sodium-calcium exchanger have a key role in AMPA receptor-mediated neurodegeneration via calpain activation in hippocampal neurons

Proteolytic cleavage of the Na(+)/Ca(2+) exchanger (NCX) by calpains impairs calcium homeostasis, leading to a delayed calcium overload and excitotoxic cell death. However, it is not known whether reversal of the exchanger contributes to activate calpains and trigger neuronal death. We investigated the role of the reversal of the NCX in Ca(2+) dynamics, calpain activation and cell viability, in alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptor-stimulated hippocampal neurons. Selective overactivation of AMPA receptors caused the reversal of the NCX, which accounted for approximately 30% of the rise in intracellular free calcium concentration ([Ca(2+)](i)). The NCX reverse-mode inhibitor, 2-[2-[4-(4-nitrobenzyloxy)phenyl]ethyl]isothiourea (KB-R7943), partially inhibited the initial increase in [Ca(2+)](i), and prevented a delayed increase in [Ca(2+)](i). In parallel, overactivation of AMPA receptors strongly activated calpains and led to the proteolysis of NCX3. KB-R7943 prevented calpain activation, cleavage of NCX3 and was neuroprotective. Silencing of NCX3 reduced Ca(2+) uptake, calpain activation and was neuroprotective. Our data show for the first time that NCX reversal is an early event following AMPA receptor stimulation and is linked to the activation of calpains. Since calpain activation subsequently inactivates NCX, causing a secondary Ca(2+) entry, NCX may be viewed as a new suicide substrate operating in a Ca(2+)-dependent loop that triggers cell death and as a target for neuroprotectio