37 research outputs found
Inducing Ni Sensitivity in the Ni Hyperaccumulator Plant Alyssum inflatum NyĂĄrĂĄdy (Brassicaceae) by Transforming with CAX1, a Vacuolar Membrane Calcium Transporter
The importance of calcium in nickel tolerance was studied in the nickel hyperaccumulator plant Alyssum inflatum by gene transformation of CAX1, a vacuolar membrane transporter that reduces cytosolic calcium. CAX1 from Arabidopsis thaliana with a CaMV35S promoter accompanying a kanamycin resistance gene was transferred into A. inflatum using Agrobacterium tumefaciens. Transformed calli were subcultured three times on kanamycin-rich media and transformation was confirmed by PCR using a specific primer for CAX1. At least 10 callus lines were used as a pool of transformed material. Both transformed and untransformed calli were treated with varying concentrations of either calcium (1â15 mM) or nickel (0â 500 lM) to compare their responses to those ions. Increased external calcium generally led to increased callus biomass, however, the increase was greater for untransformed callus. Further, increased external calcium led to increased callus calcium concentrations. Transformed callus was less nickel tolerant than untransformed callus: under increasing nickel concentrations callus relative growth rate was significantly less for transformed callus. Transformed callus also contained significantly less nickel than untransformed callus when exposed to the highest external nickel concentration (200 lM). We suggest that transformation with CAX1 decreased cytosolic calcium and resulted in decreased nickel tolerance. This in turn suggests that, at low cytosolic calcium concentrations, other nickel tolerance mechanisms (e.g., complexation and vacuolar sequestration) are insufficient for nickel tolerance. We propose that high cytosolic calcium is an important mechanism that results in nickel tolerance by nickel hyperaccumulator plants
Globular cluster systems and galaxy formation
Globular clusters are compact, gravitationally bound systems of up to a
million stars. The GCs in the Milky Way contain some of the oldest stars known,
and provide important clues to the early formation and continuing evolution of
our Galaxy. More generally, GCs are associated with galaxies of all types and
masses, from low-mass dwarf galaxies to the most massive early-type galaxies
which lie in the centres of massive galaxy clusters. GC systems show several
properties which connect tightly with properties of their host galaxies. For
example, the total mass of GCs in a system scales linearly with the dark matter
halo mass of its host galaxy. Numerical simulations are at the point of being
able to resolve globular cluster formation within a cosmological framework.
Therefore, GCs link a range of scales, from the physics of star formation in
turbulent gas clouds, to the large-scale properties of galaxies and their dark
matter. In this Chapter we review some of the basic observational approaches
for GC systems, some of their key observational properties, and describe how
GCs provide important clues to the formation of their parent galaxies.Comment: 32 pages, 6 figures. Accepted for publication in the book "Reviews in
Frontiers of Modern Astrophysics: From Space Debris to Cosmology" (eds
Kabath, Jones and Skarka; publisher Springer Nature) funded by the European
Union Erasmus+ Strategic Partnership grant "Per Aspera Ad Astra Simul"
2017-1-CZ01-KA203-03556
Combining farmers' decision rules and landscape stochastic regularities for landscape modelling
International audienceLandscape spatial organization (LSO) strongly impacts many environmental issues. Modelling agricultural landscapes and describing meaningful landscape patterns are thus regarded as key-issues for designing sustainable landscapes. Agricultural landscapes are mostly designed by farmers. Their decisions dealing with crop choices and crop allocation to land can be generic and result in landscape regularities, which determine LSO. This paper comes within the emerging discipline called "landscape agronomy", aiming at studying the organization of farming practices at the landscape scale. We here aim at articulating the farm and the landscape scales for landscape modelling. To do so, we develop an original approach consisting in the combination of two methods used separately so far: the identification of explicit farmer decision rules through on-farm surveys methods and the identification of landscape stochastic regularities through data-mining. We applied this approach to the Niort plain landscape in France. Results show that generic farmer decision rules dealing with sunflower or maize area and location within landscapes are consistent with spatiotemporal regularities identified at the landscape scale. It results in a segmentation of the landscape, based on both its spatial and temporal organization and partly explained by generic farmer decision rules. This consistency between results points out that the two modelling methods aid one another for land-use modelling at landscape scale and for understanding the driving forces of its spatial organization. Despite some remaining challenges, our study in landscape agronomy accounts for both spatial and temporal dimensions of crop allocation: it allows the drawing of new spatial patterns coherent with land-use dynamics at the landscape scale, which improves the links to the scale of ecological processes and therefore contributes to landscape ecology.L'organisation du paysage influe sur les problĂšmes environnementaux. ModĂ©liser les paysages pour les dĂ©crire Ă l'aide de formes significatives est une Ă©tage clĂ©. Les paysages agricoles sont principalement construits par les agriculteurs dont les dĂ©cision d'assolement peuvent ĂȘtre gĂ©nĂ©riques et dĂ©terminer des rĂ©gularitĂ©s dans l'organisation du paysage. Cet article contribue Ă l'agronomie des paysage qui est une discipline Ă©mergente. Nous cherchons Ă articuler les Ă©chelles du paysage et de l'exploitation agricole en dĂ©veloppant deux mĂ©thodes : l'une consiste Ă identifier les dĂ©cisions des agriculteurs par le bais d'enquĂȘtes, l'autre consiste Ă retrouver des rĂ©gularitĂ©s stochastiques dans le paysage par le bais de fouille de donnĂ©es. Nous avons appliquĂ© cette approche au paysage de la plaine de Niort en France. Les rĂ©sultats montrent que les dĂ©cisions des agriculteurs en matiĂšre de tournesol et maĂŻs sont gĂ©nĂ©riques et ont des effets sur le paysages que des mĂ©thodes de fouille de donnĂ©es rĂ©vĂšlent et quantifient
Cooperation Between the Police and Social Care in the Treatment of Alcohol and Family Violence Problems in Finland
Treatment options for patients with recurrent, symptomatic pleural effusions secondary to heart failure
âTroublingâ chastisement: a comparative historical analysis of child punishment in Ghana and Ireland
This article reviews an epochal change in international thinking about physical punishment of children from being a reasonable method of chastisement to one that is harmful to children and troubling to families. In addition, the article suggests shifts in thinking about physical punishment were originally pioneered as part and parcel of the dismantling of national laws granting fathersâ specific rights to admonish children under conventions of patria potestas. A comparative historical framework of analysis involving two case studies of Ireland and Ghana illustrates non-unilinear pathways of international convergence towards the prohibition of physical punishment. The comparative historical analysis highlights the 1930s and 1940s as an era when Ireland began to reject patria potestas and religious or judicial rulings which allowed for children to be given âa good beatingâ in family and school settings. However, from the same period, Ghana is seen to experience Christian remonstrations not to âspare the rodâ leading to the âconventionalâ tradition of âthis is how we do it hereâ. Two case studies serve to illustrate that banning physical punishment was less controversial in Ireland where allied traditions of patria potestas and disciplinarian Christian beliefs had lost their moral hegemony than in Ghana where such beliefs still held influence. The article concludes overall that normative campaigns against physical punishment of children emanate from a coherent paradigm of family policy where childcare, education, and well-being of children are embedded as everyday societal responsibilities rather than privatised or patriarchal familial obligations. The coherent model offers an alternative moral hegemony to neo-liberal and Janus-faced conceptualisations of good or âintactâ families versus âbrokenâ or âtroubledâ families