Recent progress in plant taxonomy and floristic studies in Greece

A survey of developments in plant taxonomy, floristics, and phytogeography in Greece during 2005 to 2016 is presented. Species diversity in different areas and on different scales is summarised in five maps. A list of new taxa described during this period is provided, together with their type citations and taxonomic comments where relevant; almost all of the taxa are based on Greek plant material

Multiple roles for UV RESISTANCE LOCUS8 in regulating gene expression and metabolite accumulation in arabidopsis under solar ultraviolet radiation

Photomorphogenic responses triggered by low fluence rates of ultraviolet B radiation (UV-B; 280–315 nm) are mediated by the UV-B photoreceptor UV RESISTANCE LOCUS8 (UVR8). Beyond our understanding of the molecular mechanisms of UV-B perception by UVR8, there is still limited information on how the UVR8 pathway functions under natural sunlight. Here, wild-type Arabidopsis (Arabidopsis thaliana) and the uvr8-2 mutant were used in an experiment outdoors where UV-A (315–400 nm) and UV-B irradiances were attenuated using plastic films. Gene expression, PYRIDOXINE BIOSYNTHESIS1 (PDX1) accumulation, and leaf metabolite signatures were analyzed. The results show that UVR8 is required for transcript accumulation of genes involved in UV protection, oxidative stress, hormone signal transduction, and defense against herbivores under solar UV. Under natural UV-A irradiance, UVR8 is likely to interact with UV-A/blue light signaling pathways to moderate UV-B-driven transcript and PDX1 accumulation. UVR8 both positively and negatively affects UV-A-regulated gene expression and metabolite accumulation but is required for the UV-B induction of phenolics. Moreover, UVR8-dependent UV-B acclimation during the early stages of plant development may enhance normal growth under long-term exposure to solar UV

Modelos de endemicidad a lo largo de un gradiente altitudinal en Sierra Nevada (España) y Lefka Ori (Creta, Grecia)

Aim: High mountains in the Mediterranean region of Europe are particularly rich in endemic vascular plants. We aimed to compare the altitudinal patterns of vascular plant species richness and the proportion of endemic species in two Mediterranean region: Lefka Ori on the island of Crete (Greece) and Sierra Nevada on the Iberian peninsula. Location: Sierra Nevada, Granada (Spain); Lefka Ori, Crete (Greece). Methods: Data from standardised permanent plots settings on summit sites (comprising eight plot sectors, covering the upeermost 10 altitudinal metres) of different elevations were used (GLORIA Multi-Summit approach; www.gloria.ac.at). Species numbers, rates of endemic species, and soils temperature were compared by means of ANCOVA and linear regression. Results: The two regions, though climatically similar, showed strikingly different patterns: In Sierra Nevada, the proportion of endemic vascular plants (species restricted to Sierra Nevada) showed a stepwise increase from the lowest to the highest summit. In contrast, the proportion of endemic species restricted to Crete was not significantly different between the four summits in Lefka Ori. In both regions the observed trends were largely consistent with the altitudinal distribution of the endemic species obtained from standard floras. Main conclusions: The geographic positions of the two regions, i.e. island versus mainland and the higher elevation of Sierra Nevada are suggested to be the primary causes of the observed differences. The high degree of endemism in the cold environments of Mediterranean mountains’ upper bioclimatic zones indicates a pronounced vulnerability to the impacts of climate change. A continued and intensified species monitoring in the mountains around the Mediterranean basin, therefore, should be considered as a priority research task.Objetivo: Las zonas de alta montaña en la región mediterránea europea son particularmente ricas en plantas vasculares endémicas. Nuestro objetivo es comparar los modelos altitudinales para la riqueza de plantas vasculares y la proporción de endemismos en dos regiones mediterráneas: Lefka Ori en la isla de Creta (Grecia) y Sierra Nevada en la Península Ibérica. Localización: Sierra Nevada, Granada (España); Lefka Ori, Creta (Grecia). Método: Los datos proceden de un muestreo estandarizado en varias cimas situadas a diferentes altitudes (GLORIA Multi-Summit approach; www.gloria.ac.at). El número de especies, tasas de endemicidad, y temperatura del suelo se compararon por medio de ANCOVA y regresión lineal. Resultados: Las dos regiones objeto de análisis, aunque similares climáticamente, muestran patrones llamativamente diferentes: en Sierra Nevada, la proporción de plantas vasculares endémicas (especies restringidas a Sierra Nevada) muestra un incremento gradual desde la cima más baja a la más alta. En contraste, la proporción de endemismos restringidos a Creta no fue significativamente diferente entre las cuatro cimas de Lefka Ori. Las tendencias observadas en ambas regiones fueron en gran parte consistentes con la distribución de las especies endémicas obtenida de las floras para cada región. Conclusiones principales: La posición geográfica de ambas regiones, por ejemplo. isla frente a continente, y la mayor elevación de Sierra Nevada se sugieren como las principales causas de las diferencias observadas. El alto grado de endemicidad en los ambientes fríos de las zonas bioclimáticas superiores de las montañas mediterráneas evidencia una marcada vulnerabilidad a los impactos del cambio climático. Por lo tanto, el seguimiento continuado e intensivo de las especies de montaña alrededor de la cuenca mediterránea, debería considerarse como una tarea investigadora prioritaria.He set up of the permanent plots and data collection was supported by the FP-5 project GLORIA-Europe (2001-2003) No EVK2-2000-00056 of the European Commission

Dispersion strengthening in vanadium microalloyed steels processed by simulated thin slab casting and direct charging. Part 2 - chemical characterisation of dispersion strengthening precipitates

The composition of the sub-15 nm particles in six related vanadium high strength low alloy steels, made by simulated thin slab direct charged casting, has been determined using electron energy loss spectroscopy (EELS). Such particles are considered to be responsible for dispersion hardening. For the first time, particles down to 4 nm in size have had their composition fully determined. In all the steels, the particles were nitrogen and vanadium rich and possibly slightly sub-stoichiometric carbonitrides. Equilibrium thermodynamics predicted much higher carbon to metal atomic ratios than observed in all cases so that kinetics and mechanical deformation clearly control the precipitation process. Thus it is important to formulate the steel with this in mind

Modelización de la atractividad territorial en las metrópolis

This article is a theoretical-methodological review of Territorial Attractiveness for the construction of a qualitative model. The aforementioned is one of the main contributions of this research, which is built on the basis of the revised literature. There is little bibliography on the subject: “the study of the metropolis analyzed from the Territorial Attractiveness and the marketing of cities.” Therefore, the discussions presented in the article come from other territories, it should also be noted that studying the metropolis from the marketing point view  is an area that is not very dabbled at present in Mexico; nevertheless this could represent truly significant changes if the use of these tools is enhanced. The conduct of this research was inductive in nature, taking a descriptive and analytical qualitative approach through the application of the modeling technique, which dates back from 2015 to 2018 taking four perspectives of Territorial Attractiveness. Among the important findings, it can be indicated that metropolitan areas have their own characteristics and can consciously position themselves in the minds of their citizens, public servants, tourists, investors and human capital through the adoption of a metropolitan city brand. On top of that, it assumes that all cities, including metropolises, can develop positioning strategies from competitiveness and marketing with a view to inserting themselves in the international environment.El presente artículo es una revisión teórico-metodológica de la Atractividad Territorial para la construcción de un modelo cualitativo siendo este uno de los principales aportes de la investigación, construido con base en la literatura revisada.Sobre el tema existe poca bibliografía del estudio de las metrópolis analizadas desde la Atractividad Territorial y de la Mercadotecnia de ciudades, por lo cual las discusiones presentadas en el artículo, provienen de otras escalas territoriales, aunado a eso, cabe señalar que estudiar metrópolis desde el punto de vista de la mercadotecnia es un área poco incursionada en la actualidad en México, pero que esto podría representar cambios verdaderamente significativos si se potencializa el uso de dichas herramientas. La realización de esta investigación fue de corte inductivo tomando un enfoque cualitativo de carácter descriptivo y analítico mediante la aplicación de la técnica de modelización, el cual data del 2015 al 2018 tomando cuatro perspectivas de la Atractividad Territorial. Entre los hallazgos importantes se puede indicar que las áreas metropolitanas poseen características propias y pueden posicionarse de manera consciente en la mente de su ciudadanía, servidores públicos, turistas, inversionistas, capital humano, a través de la adopción de una marca ciudad metropolitana. Y con ello, asume que todas las ciudades, incluidas las metrópolis, pueden desarrollar estrategias de posicionamiento desde la competitividad y la mercadotecnia con miras a insertarse en el medio internacional

Hydrogen peroxide contributes to the ultraviolet-B (280-315 nm) induced oxidative stress of plant leaves through multiple pathways

Solar UV-B (280-315 nm) radiation is a developmental signal in plants but may also cause oxidative stress when combined with other environmental factors. Using computer modelling and in solution experiments we show that UV-B is capable of photosensitizing hydroxyl radical production from hydrogen peroxide. We present evidence that the oxidative effect of UV-B in leaves is at least two-fold: (i) it increases cellular hydrogen peroxide concentrations, to a larger extent in pyridoxine antioxidant mutant pdx1.3-1 Arabidopsis and (ii) is capable of a partial photo-conversion of both ‘natural’ and ‘extra’ hydrogen peroxide to hydroxyl radicals. As stress conditions other than UV can increase cellular hydrogen peroxide levels, synergistic deleterious effects of various stresses may be expected already under ambient solar UV-B