Search results for "Maran"

2018

This study aims to identify the histological basis for the extraordinary, fast movement of the style in Marantaceae. Although this explosive pollination mechanism was subject of many studies, quantitative measurements to document volumetric changes have never been conducted. Based on physical parameters and limitations (poroelastic time), the movement itself is by far too fast to be explained by turgor changes solely. Therefore, we address the hypothesis that the style contains elastic structures to store energy allowing the fast movement. We provide an experimental approach in Goeppertia bachemiana to identify histological differences of styles in various states, i.e., steady, unreleased, …

Sociología, Derecho y desigualdades sociales. Una propuesta de docencia universitaria crítica

2019

Fil: Di Nella, Dino. Universidad Nacional de Río Negro. Río Negro, Argentina. Fil: Almeda, Elisabet. Universidad de Barcelona. Catalunya, España. Fil: Camps Calvet, Clara. Universidad de Barcelona. Catalunya, España. Fil: Giordana, Patricia. Universidad Nacional de Río Negro. Río Negro, Argentina. Fil: Loggiacco, Camila. Universidad Nacional de Río Negro. Río Negro, Argentina. Fil: D'Alfonso, Luis. Universidad Nacional de Río Negro. Río Negro, Argentina. Critic education in human rights and social inequalities must be able to capture holistic and mutidmiensional sphere that Human Rights requires. This study introduces the basis in which critic university teaching proposal is carectarized by…

A broader model for C 4 photosynthesis evolution in plants inferred from the goosefoot family (Chenopodiaceae s.s.)

2012

C 4 photosynthesis is a fascinating example of parallel evolution of a complex trait involving multiple genetic, biochemical and anatomical changes. It is seen as an adaptation to deleteriously high levels of photorespiration. The current scenario for C 4 evolution inferred from grasses is that it originated subsequent to the Oligocene decline in CO 2 levels, is promoted in open habitats, acts as a pre-adaptation to drought resistance, and, once gained, is not subsequently lost. We test the generality of these hypotheses using a dated phylogeny of Amaranthaceae s.l. (including Chenopodiaceae), which includes the largest number of C 4 lineages in eudicots. The oldest chenopod C 4 lineage da…

Disentangling Sources of Gene Tree Discordance in Phylogenomic Data Sets: Testing Ancient Hybridizations in Amaranthaceae s.l.

2019

AbstractGene tree discordance in large genomic data sets can be caused by evolutionary processes such as incomplete lineage sorting and hybridization, as well as model violation, and errors in data processing, orthology inference, and gene tree estimation. Species tree methods that identify and accommodate all sources of conflict are not available, but a combination of multiple approaches can help tease apart alternative sources of conflict. Here, using a phylotranscriptomic analysis in combination with reference genomes, we test a hypothesis of ancient hybridization events within the plant family Amaranthaceae s.l. that was previously supported by morphological, ecological, and Sanger-base…

Amaranthus grain as a new ingredient in diets for dairy cows: productive, qualitative, and in vitro fermentation traits

2022

Background: In recent decades, grain amaranths have attracted attention due to their valuable combination of nutritional traits, with higher protein and oil content than conventional cereals. Before they can be proposed as an unconventional ingredient in animal feed, many aspects still need to be investigated from field production to nutritive value. The present research aimed to study the agronomic traits, proximate composition, and digestibility/degradability, fatty acid profile, antioxidant activity, and total phenolic content of two grain amaranth species, Amaranthus cruentus and Amaranthus hypochondriacus (for a total of six accessions), grown in a Mediterranean environment. Results: B…

Theoretical study of a Bénard Marangoni problem

2011

[EN] In this paper we prove the existence of strong solutions for the stationary Benard-Marangoni problem in a finite domain flat on the top, bifurcating from the basic heat conductive state. The Benard-Marangoni problem is a physical phenomenon of thermal convection in which the effects of buoyancy and surface tension are taken into account. This problem is modelled with a system of partial differential equations of the type Navier-Stokes and heat equation. The boundary conditions include crossed boundary conditions involving tangential derivatives of the temperature and normal derivatives of the velocity field. To define tangential derivatives at the boundary, intended in the trace sense,…

Influence of the Electromagnetic, G-Jitter or Thermocapillary Forces on the Stability of the Stationary Buoyancy Convection

1992

Microgravity conditions seem to be very useful for crystal growth processes. Reduced gravitational force strongly weakens the buoyancy convection, so the convective oscillations in the melt become impossible [1]. This is the main reason of numerous attempts to obtain monocrystal materials with homogeneous internal structure in microgravity. On the other hand for non-isothermal fluid in microgravity conditions other driving forces become more significant than on the Earth. The main of them are thermocapillarity and g-jitter. The thermocapillary forces exist on the non-uniformly heated free liquid surfaces and cause motion of the fluid. The g-jitter appears in space unavoidably because of the…

Influence of growth parameters and melt convection on the solid-liquid interface during RF-floating zone crystal growth of intermetallic compounds

2001

Abstract The influence of growth parameters and melt convection on the solid–liquid interface of the intermetallic compound Ni3Si grown by the RF-floating zone technique was investigated experimentally as well as numerically. Numerical simulations showed that the heat transfer is strongly influenced by the electromagnetically driven and Marangoni convections whereas both the buoyancy and feed rotation have a negligible effect. It was found experimentally that the inductor design, the rod diameter and the length of the molten zone influence the solid–liquid interface shape significantly. The electromagnetically driven convection increases dramatically with increasing zone length due to the r…

Modeling of Melt Flow and Heat Transfer in Stationary Gas Tungsten Arc Welding with Vertical and Tilted Torches

2021

A 3D numerical simulation was conducted to study the transient development of temperature distribution in stationary gas tungsten arc welding with filler wire. Heat transfer to the filler wire and the workpiece was investigated with vertical (90°) and titled (70°) torches. Heat flux, current flux, and gas drag force were calculated from the steady-state simulation of the arc. The temperature in the filler wire was determined at three different time intervals: 0.12 s, 0.24 s, and 0.36 s. The filler wire was assumed not to deform during this short time, and was therefore simulated as solid. The temperature in the workpiece was calculated at the same intervals using heat flux, current flux, ga…

Vibrio palustris sp. nov. and Vibrio spartinae sp. nov., two novel members of the Gazogenes clade, isolated from salt-marsh plants (Arthrocnemum macr…

2017

Two bacterial strains, EAod9T and SMJ21T, isolated from salt-marsh plants, were determined to be related to species of the genus Vibrio from from 16S rRNA sequence comparisons. Their closest phylogenetic relatives are members of the Gazogenes clade, Vibrio mangrovi and Vibrio rhizosphaerae , which show the greatest similarity to the SMJ21TrRNA sequence (97.3 and 97.1 %, respectively), while EAod9T had less than 97.0 % similarity to any other species of the genus Vibrio . Both strains share the basic characteristics of the genus Vibrio , as they are Gram-stain negative, motile, slightly halophilic, facultatively anaerobic bacteria. In addition, they are oxidase-negative and unable to grow on…