High genetic diversity and clonal growth in relict populations of Olea europaea subsp. laperrinei (Oleaceae) from Hoggar, Algeria.

The Laperrine's olive (Olea europaea subsp. laperrinei) is an endemic tree from Saharan massifs. Its populations have substantially regressed since the Pleistocene and are presently distributed in a fragmented habitat. Long-term persistence of this taxon is uncertain and programmes of preservation have to be urgently implemented. To define a conservation strategy, the genetic diversity and breeding system of this tree have to be investigated. One hundred and eleven ramets were prospected in the laperrinei populations from the Tamanrasset region, southern Algeria. Genetic polymorphism was revealed at nuclear and chloroplast DNA (cpDNA) microsatellite loci allowing a comparative assessment of the genetic diversity of laperrinei and Mediterranean populations based on bi-parental and maternal markers. Additionally, nuclear microsatellite markers enabled the genotypes to be identified unambiguously. Based on nuclear microsatellite data, the total diversity was high (Ht=0.61) in laperrinei populations and similar to that observed in western Mediterranean populations. A substantial cpDNA diversity (Ht=0.19) was also observed. Genetically identical ramets originated from the same stump (which can cover >80 m2) were identified in each population. Sixteen per cent of genets exhibited more than one ramet. In addition, several cases of somatic mutations were unambiguously revealed in distinct ramets stemming from the same stump. These data show that highly isolated and small laperrinei populations are able to maintain a high genetic diversity. This supports the existence of relict trees persisting for a very long time (probably since the last humid transition, 3000 years ago). It is proposed that the very long persistence associated with an asexual multiplication of highly adapted trees could be a strategy of survival in extreme conditions avoiding a mutational meltdown due to reproduction in reduced populations

Estudios ultraestructurales y citoquímicos de huéspedes y patógenos en algunas enfermedades de marchitamiento fúngicas: una retro e introspeción dirigida al mejor entendimiento de DED

This report presents a survey of previous and more recent ultrastructural and cytochemical investigations of disease development in elm, caused by Ophiostoma novo-ulmi, with results of some comparative studies of other wilt diseases caused by f.spp., of Fusarium oxysporum and of Verticillium sp. For cytochemical studies, probes complexed to colloidal gold to detect cellulose, pectin, chitin, and DNA were used. Thus, the formation of tyloses, pit membrane alterations, and the disease effect on parenchyma cells in mature as well as in young tissue were characterized. Vessel lumina in these plants, in diverse situations, contained heterogeneous matter, among which occurred masses of opaque matter and in certain instances pectin fibrils secreted by parenchyma cells and tyloses. Numerous globoid, opaque bodies of regular sizes, which have been mostly overlooked previously, abounded in vessel elements of U. americana and U. glabra, including trees injected with glucose solutions prior to inoculation. Coarser fibrillar material was also noted in vessel lumina, but mostly shortly after inoculation. Other peculiar forms of O. novo-ulmi are also described. The possible role of the components under study is discussed, and a model for DED is proposed in which hindrance to vessel invasion, including downward spread of the pathogen, and reactions of parenchyma cells are complementary and considered to be conducive to defence mechanisms, including compartmentalization of the invaded xylem.En este informe se presenta una revisión de los más recientes estudios sobre la ultraestructura y la citoquímica del desarrollo infectivo causado por Ophiostoma novo-ulmi en el olmo, y su comparación con otras enfermedades vasculares causada por hongos como Fusarium oxysporum y Verticillium sp. En los estudios citoquímicos se usaron inmunolocalizadores de oro coloidal para la detección de celulosa, pectina, quitina y ADN. De esta manera se caracterizó la formación de tilosas, las alteraciones en las punteaduras, y los efectos de la infección en las células parenquimáticas, tanto en tejidos adultos como jóvenes. En estas plantas, el interior de los elementos conductores contiene, en diversas ocasiones, sustancias heterogéneas en las que aparecen masas de sustancias opacas, así como, en ciertas ocasiones, fibrillas de pectina segregadas por células parenquimáticas y por tilosas. Numerosos cuerpos opacos globulares de tamaño medio, que previamente habían pasado en gran medida inadvertidos, eran abundantes en los elementos conductores de U. americana y U. glabra, incluyendo árboles a los que se inyectó soluciones de glucosa antes de la inoculación. También se detectó la presencia, en el interior de los vasos, de material fibrilar de mayor diámetro, sobre todo al poco de la inoculación. También se describen otras formas peculiares de O. novo-ulmi. Se discute el posible papel de los componentes en estudio, y se propone un modelo para la grafiosis en el cual los obstáculos para la invasión del vaso, incluidas la transmisión corriente abajo del patógeno y la reacción de células parenquimáticas, son complementarios, considerándose que son conducentes a la aparición de mecanismos de defensa, incluida la compartimentación del xilema invadido

Sustainability, Globalization, and the Energy Sector Europe in a Global Perspective

International audienceThis paper analyzes the socio-economic effects of energy sustainability challenges raised by oil depletion and climate change at the European and global level. We assess macroeconomic impacts at different time horizons over 2010-2100 and under different visions of the future of globalization . Fragmented capital markets affect the pace and direction of change and induce additional economic losses in the long term. Regionalized good markets have a positive effect in the long term since less intense international trade moderates the effects of fossil fuel constraints. A sustainable energy future will require implementing policies and measures that are able to (i) provide correct incentives for long-term investments by resorting to other signals than current market prices, (ii) incorporate sectoral measures that act complementarily to pricing schemes measures for sectors confronted with biased agents’ behaviors or strong inertias, (iii) foster globalization patterns that are consistent with energy sustainability objectives. The challenge consists in articulating the objectives and the instruments of these different policy and measures triggering the transition towards sustainable future

Protein Phosphatase 1 Beta is Modulated by Chronic Hypoxia and Involved in the Angiogenic Endothelial Cell Migration

Background/Aim: Endothelial cell migration is required for physiological angiogenesis, but also contributes to various pathological conditions, including tumour vascularization. The mRNA expression of PP1cβ, the beta isoform of the catalytic PP1 subunit, was shown to be upregulated in chronic hypoxia. Since hypoxia is a major regulator of angiogenesis, the potential role of PP1cβ in angiogenesis was investigated. Methods: We examined PP1cβ protein level in pediatric heart following chronic hypoxia and found PP1cβ upregulation in cyanotic compared with acyanotic myocardium. By treating HUVEC cells with hypoxia mimicking agent, PP1cβ protein level increased with maximum at 8 hours. The effect of PP1cβ pharmacological inhibition, knockdown and overexpression, on endothelial cell migration and morphogenesis, was examined using in vitro wound healing scratch assay and endothelial tube formation assay. The PP1cβ knockdown effects on F-actin reorganization (phalloidin staining), focal adhesion formation (vinculin) and focal adhesion kinases (FAK) activation, were evaluated by immunocytochemical staining and immunoblotting with specific antibodies. Results: PP1cβ knockdown significantly reduces endothelial cell migration, but does not have any significant effect on endothelial tube formation. Endothelial cell migration in the knockdown group is restored to the control level upon consecutive transfection with PP1cβ cDNA. PP1cβ overexpression does not significantly affect endothelial cell migration. Furthermore, PP1cβ knockdown induces profound cytoskeletal reorganization, loss of focal adhesion sites and impairment of focal adhesion kinases (FAK) activation. Conclusions: PP1cβ is regulator of endothelial cell migration, which is critical in the angiogenic process. PP1cβ inhibition reduces endothelial cell migration through focal adhesion turnover and actin polymerization pathways

Ultraestructura de la red alveolar y su relación con el recubrimiento de las paredes vasculares en olmos infectados con Ophiostoma novo-ulmi y en otras plantas infectadas con enfermedades similares de marchitamiento

In elms infected with Dutch elm disease, alveolar networks, demarcated by filamentous-like bands and confluent with similar matter (the coating) accumulating on vessel walls, occurred regularly in vessel elements. Similar material lined vessel walls in inoculated, sterilized, thin elm wood sections fixed by high pressure freezing. The coating was observed to connect with fungal cells and occasionally contained small opaque particles, the size of ribosomes, membranous and vesicular structures, and, following incubation of wood chips taken from diseased samples incubated on an agar medium, it still displayed similar matter. Coating and alveolar bands increased in thickness by confluence of other bands or membranous structures. Similar matter and structures also occurred in other plants affected by similar fungal wilt diseases. In all systems, the compact coating did not label for chitin, cellulose and pectin. In staghorn sumac, the probe for DNA attached to the coating. Altogether, in the light of these data, it appears that the coating and alveolar networks are not inert components, a fact which indicates their primordial probable pathogen origin. It is proposed that these elements might be important not only in the initial infection stages but also in older or recurrent infections at a time when host resistance mechanisms are ineffective.En olmos afectados por la grafiosis, la red alveolar, demarcada por bandas filamentosas, y confluente con acumulaciones de la misma sustancia (cubrición) presentes en las paredes de los vasos, aparece regularmente en los elementos conductores. Sustancias similares tapizan las paredes de los vasos en secciones de madera delgada de olmo inoculada y esterilizada, y posteriormente criofijadas a altas presiones. Se observó que la cubrición se conecta con las células del micelio y que ocasionalmente contenía pequeñas partículas opacas del tamaño de los ribosomas, estructuras membranosas y vesiculares, así como que, tras la incubación de astillas leñosas cogidas de muestras enfermas incubadas en agar, aún se presentaba una sustancia similar. La cubrición y las bandas alveolares aumentaron su espesor en la confluencia con otras bandas o estructuras membranosas. Estructuras y sustancias similares aparecieron también en otras plantas afectadas por enfermedades similares originadas por hongos que producen marchitamiento. En todos los sistemas, la cubrición compacta no pudo ser marcada como quitina, celulosa ni pectina. En zumaque (Rhus typhina), la sonda de ADN se pegó a la cubrición. En resumen, a la vista de estos datos, parece ser que la cubrición y la red alveolar no están formados por componentes inertes, un hecho que indica su probable origen patogénico. Se sugiere que esos elementos podrían ser importantes no sólo en las fases iniciales de la infección, sino también, en infecciones más desarrolladas o recurrentes, en el momento en que los mecanismos de resistencia del hospedante no son efectivos

Cliophysics: Socio-political Reliability Theory, Polity Duration and African Political (In)stabilities

Quantification of historical sociological processes have recently gained attention among theoreticians in the effort of providing a solid theoretical understanding of the behaviors and regularities present in sociopolitical dynamics. Here we present a reliability theory of polity processes with emphases on individual political dynamics of African countries. We found that the structural properties of polity failure rates successfully capture the risk of political vulnerability and instabilities in which 87.50%, 75%, 71.43%, and 0% of the countries with monotonically increasing, unimodal, U-shaped and monotonically decreasing polity failure rates, respectively, have high level of state fragility indices. The quasi-U-shape relationship between average polity duration and regime types corroborates historical precedents and explains the stability of the autocracies and democracies.Comment: 4 pages, 3 figures, 1 tabl

Structural and magnetic properties of Co2MnSi thin films

Co2MnSi (CMS) films of different thicknesses (20, 50, and 100 nm) were grown by radio frequency (RF) sputtering on a-plane sapphire substrates. Our X-rays diffraction (XRD) study shows that, in all the samples, the cubic 〈110〉 CMS axis is normal to the substrate and that six well defined preferential in-plane orientations are present. Static and dynamic magnetic properties were investigated using vibrating sample magnetometry (VSM) and microstrip line ferromagnetic resonance (MS-FMR), respectively. From the resonance measurements versus the direction and the amplitude of an applied magnetic field, most of the magnetic parameters are derived, i.e.: the magnetization, the gyromagnetic factor, the exchange stiffness coefficient, and the magnetic anisotropy terms. The in-plane anisotropy results from the superposition of two terms showing a twofold and a fourfold symmetry, respectively. The observed behavior of the hysteresis loops is in agreement with this complex form of the in-plane anisotropy.International audienceCo2MnSi (CMS) films of different thicknesses (20, 50, and 100 nm) were grown by radio frequency (RF) sputtering on a-plane sapphire substrates. Our X-rays diffraction (XRD) study shows that, in all the samples, the cubic 〈110〉 CMS axis is normal to the substrate and that six well defined preferential in-plane orientations are present. Static and dynamic magnetic properties were investigated using vibrating sample magnetometry (VSM) and microstrip line ferromagnetic resonance (MS-FMR), respectively. From the resonance measurements versus the direction and the amplitude of an applied magnetic field, most of the magnetic parameters are derived, i.e.: the magnetization, the gyromagnetic factor, the exchange stiffness coefficient, and the magnetic anisotropy terms. The in-plane anisotropy results from the superposition of two terms showing a twofold and a fourfold symmetry, respectively. The observed behavior of the hysteresis loops is in agreement with this complex form of the in-plane anisotropy

UNDRAINED BEARING CAPACITY OF EMBEDDED STRIP FOOTINGS UNDER VERTICAL AND HORIZONTAL LOADS

This paper is concerned with the undrained bearing capacity of embedded strip footing under inclined loading (i.e. combined vertical and horizontal). A series of numerical computations using the finite-difference code Fast Lagrangian Analysis of Continua (FLAC) was carried out to evaluate the failure envelopes in vertical force – horizontal force (V-H) plane, using both probe and swipe analyses. The adopted approach involves a numerical solution of the equations governing elasto-plastic soils. The soil is modeled by an elasto-plastic model with a Tresca criterion. The results are presented in terms of the failure envelope in vertical and horizontal loading plane. 

Second T = 3/2 state in 9^9B and the isobaric multiplet mass equation

Recent high-precision mass measurements and shell model calculations~[Phys. Rev. Lett. {\bf 108}, 212501 (2012)] have challenged a longstanding explanation for the requirement of a cubic isobaric multiplet mass equation for the lowest $A = 9$ isospin quartet. The conclusions relied upon the choice of the excitation energy for the second $T = 3/2$ state in $^9$B, which had two conflicting measurements prior to this work. We remeasured the energy of the state using the $^9{\rm Be}(^3{\rm He},t)$ reaction and significantly disagree with the most recent measurement. Our result supports the contention that continuum coupling in the most proton-rich member of the quartet is not the predominant reason for the large cubic term required for $A = 9$ nuclei