131 research outputs found
Allylsulfones through Palladium-Catalyzed Allylic C−H Sulfonylation of Terminal Alkenes
Two previously unknown protocols for Pd-catalyzed allylic C-H sulfonylation of terminal alkenes have been developed. While the former consists of a direct Pd(II)-catalyzed oxidative C-H allylic sulfonylation in the presence of sulfinate anions, the latter involves a sequential one-pot Pd(II)-catalyzed C-H allylic acetoxylation followed by a Pd(0)-catalyzed sulfonylation. The scope of both protocols was studied on 25 examples
Berry size variability in Vitis vinifera L.
In order to study the mechanisms of berry growth in Vitis vinifera L. we analysed cell division and pericarp enlargement of 6 genotypes showing high variability in berry size (range: 49-90 %. Both, cell number and cell volume were involved in the small-sized berries of the flb mutant producing wild-type-like berries. The differences of berry size observed in other small-sized clones were only due to cell expansion. The data suggest that the variability of berry size in V. vinifera cultivars predominantly results from modification of cell enlargement. Conversely, in wild-type-like berries, the variability of berry size could result from both, cell division and cell enlargement.
Microwave-Induced Combustion Synthesis of Luminescent Aluminate Powders
ISBN 978-953-51-0371-4 Chapitre
Concentração de ferro anormalmente aumentada nos núcleos da base na síndrome de Shy-Drager
Report of an early case of Shy-Drager syndrome in a 67 year-old woman patient. Autonomic failure was diagnosed by functional evaluation as well as laboratory tests. MR imaging disclosed a prominent putamina hypodensity in T2-weighted images at high field strength due to iron increased depositing in this basal ganglia. MR imaging evidences confirm Shy-Drager syndrome diagnosis, and contributes for differential diagnosis of idiopathic hypotension (pure autonomic failure) in special in SDS early cases.É relatado o caso de unm paciente de 67 anos de idade com quadro inicial da síndrome de Shy-Drager. O diagnóstico foi possível por provas funcionais autonômicas e exames laboratoriais. A ressonância magnética cerebral (contraste baseado na densidade de prótons e em T2) objetivou proeminente hipodensidade putaminal em T2, secundária ao aumento do depósito do ferro nesta região. Esse achado da RM confirma o diagnóstico da síndrome de Shy-Drager e permite diferenciá-la da hipotensão ortostática idiopática, particularmente na fase de início da SSD quando os sinais de comprometimento do SNC são discretos ou estão ausentes.34234
Cellular localisation of VvRops and VvRabA5e, small GTPases developmentally regulated in grape berries
VvRops, in particular VvRop9, and VvRabA5e are small GTPases which are developmentally regulated in grape berries. In an attempt to help elucidate the role of these proteins during fruit development and ripening, we investigated their localisation in the fruit by immunocytofluorescence. These proteins were observed at a perinuclear location, at cell periphery and around vesicles. In particular VvRops were found to be located in the nucleus and likely on the plasma membrane. VvRop9 and VvRabA5e cDNAs were introduced separately into S. cerevisiae mutants with RHO1 and YPT31/YPT32 defective genes respectively. Neither cDNAs could complement these temperature-sensitive mutants, suggesting that the functions of the VvRop9 and VvRabA5e genes in grapevine likely differ from the functions of RHO1 and YPT31/YPT32 genes in yeast.
Tipping points in overturning circulation mediated by ocean mixing and the configuration and magnitude of the hydrological cycle: A simple model
The current configuration of the ocean overturning involves upwelling
predominantly in the Southern Ocean and sinking predominantly in the Atlantic
basin. The reasons for this remain unclear, as both models and paleoclimatic
observations suggest that sinking can sometimes occur in the Pacific. We
present a six-box model of the overturning in which temperature, salinity and
low-latitude pycnocline depths are allowed to vary prognostically in both the
Atlantic and Pacific. The overturning is driven by temperature, winds, and
mixing and modulated by the hydrological cycle. In each basin there are three
possible flow regimes, depending on whether low-latitude water flowing into
northern surface boxes is transformed into dense deep water, somewhat lighter
intermediate water, or light water that is returned at the surface. The
resulting model combines insights from a number of previous studies and allows
for nine possible global flow regimes. For the modern ocean, we find that
although the interbasin atmospheric freshwater flux suppresses Pacific sinking,
the equator-to-pole flux enhances it. When atmospheric temperatures are held
fixed, seven possible flow regimes can be accessed by changing the amplitude
and configuration of the modern hydrological cycle . North Pacific overturning
can strengthen with either increases or decreases in the hydrological cycle, as
well as under reversal of the interbasin freshwater flux. Tipping-point
behavior of both transient and equilibrium states is modulated by parameters
such as the poorly constrained lateral diffusive mixing. If hydrological cycle
amplitude is varied consistently with global temperature, northern polar
amplification is necessary for the Atlantic overturning to collapseComment: 38 pages, 10 figures, Submitted to Journal of Physical Oceanograph
Morphological Plant Modeling: Unleashing Geometric and Topological Potential within the Plant Sciences
The geometries and topologies of leaves, flowers, roots, shoots, and their arrangements have fascinated plant biologists and mathematicians alike. As such, plant morphology is inherently mathematical in that it describes plant form and architecture with geometrical and topological techniques. Gaining an understanding of how to modify plant morphology, through molecular biology and breeding, aided by a mathematical perspective, is critical to improving agriculture, and the monitoring of ecosystems is vital to modeling a future with fewer natural resources. In this white paper, we begin with an overview in quantifying the form of plants and mathematical models of patterning in plants. We then explore the fundamental challenges that remain unanswered concerning plant morphology, from the barriers preventing the prediction of phenotype from genotype to modeling the movement of leaves in air streams. We end with a discussion concerning the education of plant morphology synthesizing biological and mathematical approaches and ways to facilitate research advances through outreach, cross-disciplinary training, and open science. Unleashing the potential of geometric and topological approaches in the plant sciences promises to transform our understanding of both plants and mathematics
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