3,720 research outputs found
(2479) Proposal to conserve the name Marattia kaulfussii (Eupodium kaulfussii) against M. raddiana (Marattiaceae)
Proposal to conserve the name Marattia kaulfussii (Eupodium kaulfussii)against M. raddiana (Marattiaceae). Unless this proposal is accepted, the epithet raddiana will need to be combined under Eupodium and this will become the correctname of what is universally known as E. kaulfussii. Conservation of M. kaulfussii against M. raddiana is therefore seen as the best solution in the interest of nomenclatural stability.Fil: Arana, Marcelo Daniel. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Ciencias Naturales; ArgentinaFil: Christenhusz, MaartenJ.M.. Royal Botanic Gardens; Reino UnidoFil: Ponce, Marta Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentin
Constraining the high redshift formation of black hole seeds in nuclear star clusters with gas inflows
In this paper we explore a possible route of black hole seed formation that
appeal to a model by Davies, Miller & Bellovary who considered the case of the
dynamical collapse of a dense cluster of stellar black holes subjected to an
inflow of gas. Here, we explore this case in a broad cosmological context. The
working hypotheses are that (i) nuclear star clusters form at high redshifts in
pre-galactic discs hosted in dark matter halos, providing a suitable
environment for the formation of stellar black holes in their cores, (ii) major
central inflows of gas occur onto these clusters due to instabilities seeded in
the growing discs and/or to mergers with other gas-rich halos, and that (iii)
following the inflow, stellar black holes in the core avoid ejection due to the
steepening to the potential well, leading to core collapse and the formation of
a massive seed of . We simulate a cosmological box
tracing the build up of the dark matter halos and there embedded baryons, and
explore cluster evolution with a semi-analytical model. We show that this route
is feasible, peaks at redshifts and occurs in concomitance with the
formation of seeds from other channels. The channel is competitive relative to
others, and is independent of the metal content of the parent cluster. This
mechanism of gas driven core collapse requires inflows with masses at least ten
times larger than the mass of the parent star cluster, occurring on timescales
shorter than the evaporation/ejection time of the stellar black holes from the
core. In this respect, the results provide upper limit to the frequency of this
process
Finite-discrete element modelling of masonry infill walls subjected to out-of-plane loads
In this paper, the out-of-plane response of infill walls is investigated by means of non-linear monotonic (push-over) analyses through a combined finite and discrete modelling approach. The model accounts for material deformability, crack formation, sliding, separa-tion and formation of new contacts. Masonry units are modelled as finite elements, and differ-ent material models are assumed for the masonry. Contact between masonry units, and between masonry and frame elements is modelled by means of interfaces, which permit tan-gential motion with frictional sliding. Frame elements are modelled by means of a linear-elastic material. The results of the numerical analyses are compared with those of experimen-tal tests available in the literature. The advantages and disadvantages of the adopted model-ling strategy are investigated
The family Lindsaeaceae in Argentina
Se realiza un análisis morfológico de la familia de helechos Lindsaeaceae en la Argentina, y se actualizan los datos de su distribución. A partir de la rectificación de información previa debida a citas no corroboradas y erróneas determinaciones se confirma la presencia de un único taxón en el país: Lindsaea quadrangularis subsp. terminalis. Se provee una descripción morfológica detallada, consideraciones sobre el hábitat, notas relevantes, ilustraciones, fotografías y un mapa de distribución de la especie en el área de estudio. Se elabora una clave para identificar las especies del género Lindsaea para la Argentina y áreas limítrofes de Brasil.A morphological analysis of the fern family Lindsaeaceae from Argentina is carried out and distributional data updated. After the rectification of previous information due to citations uncorroborated and erroneous determinations the presence of a single taxon is confirmed in the country: Lindsaea quadrangularis subsp. terminalis . A detailed morphologic description, habitat considerations, relevant notes, illustrations, photographs and a distribution map are provided for the species. A comprehensive key to identify the species of Lindsaea from Argentina and neighboring areas of Brazil is made.Fil: Yañez, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: Ponce, Marta Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentin
Influence of temperature on liquid - liquid equilibrium of methanol + toluene + hexane ternary system at atmospheric pressure
Abstract Liquid-liquid equilibrium of methanol + toluene+ hexane ternary system at 278.15,283.15, 288.15 and 293.15 K are reported. The effect of the temperature on liquid-liquidequilibrium is discussed. All chemicals were quantified by gas chromatography using athermal conductivity detector. Experimental data for the ternary system are compared withvalues calculated by the NRTL and UNIQUAC equations. It is found that the UNIQUACequation fitted to the experimental data is more accurate than the NRTL model for thisternary system for all temperatures studied.Fil: Veliz, Jonatan Hernan. Instituto de Física del Noroeste Argentino, INFINOA (CONICET-UNT); ArgentinaFil: Cases, Alicia Marta. Universidad Nacional de Tucumán; ArgentinaFil: Varas Gutierrez, Constanza Geraldine. Universidad Nacional de Tucumán; ArgentinaFil: Gramajo, Monica Beatriz. Instituto de Física del Noroeste Argentino, INFINOA (CONICET-UNT); Argentin
Amauropelta opposita (Thelypteridaceae), new record for the Argentinean flora
Amauropelta opposita, una especie conocida hasta ahora para el sur de Brasil como su límite de distribución más austral, fue recolectada por primera vez en el noreste de Argentina (Misiones). Se incluyen sus características morfológicas, sinonimia y lectotipificación; se brindan ilustraciones, fotografías, un mapa con la ubicación de la nueva cita, así como una clave para la identificación de las especies de Amauropelta que habitan en Misiones.Amauropelta opposita, a species known up to now for southern Brazil as its southernmost distribution limit, was collected for the first time in northeasternArgentina (Misiones). Its morphological characteristics, synonymy and lectotypification are included; illustrations, photographs, a map with the location of the new record, as well as a key of the species of Amauropelta that live in Misiones are provided.Fil: Ponce, Marta Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Zanotti, Christian Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentin
What if young z>9 JWST galaxies hosted massive black holes?
JWST is discovering star forming `candidate' galaxies with photometric
redshifts and little attenuation. We model presumptive massive black
holes (MBHs) in such galaxies and find that their unobscured emission is
fainter than the galaxy starlight in JWST filters, and difficult to be detected
via color-color selection, and X-ray and radio observations. Only MBHs
overmassive relative to expected galaxy scaling relations, accreting at high
Eddington rates, would be detectable. Their discovery would point to the
presence of heavy MBH seeds, but care is needed to exclude the existence of
lighter seeds as only overmassive MBHs are detectable in this type of galaxies.
Conversely, if no overmassive MBHs are hosted in these galaxies, either there
are no heavy seeds or they are rare. The most massive/highest redshift
candidate galaxies can attain stellar masses in excess of 5e10 Msun by z~6 if
they grow along the SFR-mass sequence, and can nurse a MBH growing from ~1e5
Msun up to >3e7 Msun by z~6, to become hosts of some z>6 quasars. Candidate
galaxies of log(M_{gal}/Msun)~8 can not grow their putative seeds fast, unless
seeds are >1e6 Msun. The number density of the JWST candidate galaxies far
outnumbers that of the highest-z quasar hosts and this allows for about only 1
high-redshift quasar every 1000 of these galaxies.Comment: Submitted to MNRA
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Design of an anti-inflammatory diet (ITIS diet) for patients with rheumatoid arthritis.
Background:Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease that affects synovial joints, leading to inflammation, joint destruction, loss of function, and disability. Although recent pharmaceutical advances have improved treatment of RA, patients with RA often inquire about dietary interventions to improve RA symptoms, as they perceive rapid changes in their symptoms after consumption of certain foods. There is evidence that some ingredients have pro- or anti-inflammatory effects. In addition, recent literature has shown a link between diet and microbiome changes. Both diet and the gut microbiome are linked to circulating metabolites that may modulate inflammation. However, evidence of the effects of an anti-inflammatory and probiotic-rich diet in patients with RA is scarce. There is also a need for biological data to support its anti-inflammatory effects. Methods:The main goal of this study is to delineate the design process for a diet tailored to our RA population. To achieve this goal, we collected information on diet, supplements, cooking methods, and intake of different ingredients for each patient. Different groups were interviewed, and their feedback was assessed to design a diet that incorporates suggested anti-inflammatory ingredients in a manner that was easy for patients to adopt based on their lifestyles and backgrounds. Results:We designed a diet that includes a high intake of potential anti-inflammatory ingredients. Feedback from highly motivated patients was critical in constructing an anti-inflammatory diet (ITIS diet) with elevated adherence. Conclusion:In order to tailor our diet, we surveyed our patients on several different parameters. We obtained important feedback on how feasible our ITIS diet is for RA patients. Using this feedback, we made minor improvements and finalized the design of the ITIS diet. This diet is being used in an on-going pilot study to determine their anti-inflammatory effect in pain and joint swelling in RA patients. Trial registration:Not applicable
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