625 research outputs found
Sull'antagonismo in vivo ed in vitro di Acremonium byssoides, endofita in Vitis vinifera, nei confronti di Plasmopara viticola
Lo studio dell\u2019interazione fra Acremonium byssoides, Vitis vinifera e
Plasmopara viticola, condotto nell\u2019ultimo decennio, ha evidenziato in vitro e in vivo
l\u2019attivit\ue0 antagonistica dell\u2019ifomicete, endofita negli organi verdi di alcune cultivars
di vite, nei confronti del patogeno. In particolare, \ue8 stato accertato che sospensioni
conidiche, filtrati colturali, estratti grezzi e metaboliti di A. byssoides riducono
sensibilmente la germinazione delle spore agamiche e gamiche di P. viticola, limitando
la produzione di propaguli. Inoltre, l\u2019uso di un microscopio laser confocale e l\u2019impiego
di un\u2019opportuna tecnica di decolorazione dei tessuti fogliari, seguita da colorazione
di contrasto, ha consentito di visualizzare l\u2019ifomicete, latente nelle nervature di
foglie sane e iperparassita dell\u2019oomicete in foglie infette. In queste ultime, infatti, A.
byssoides, dopo aver prodotto metaboliti secondari tossici per P. viticola, ne invade e
degrada micelio, rami sporangiofori e spore gamiche.
Tale attivit\ue0 antagonistica, determinando il contenimento sia della diffusione
che della sopravvivenza del patogeno, pu\uf2 assumere, quindi, un ruolo rilevante nella
definizione di strategie di difesa biologica contro la peronospora della vite
Phase Ordering Dynamics of the O(n) Model - Exact Predictions and Numerical Results
We consider the pair correlation functions of both the order parameter field
and its square for phase ordering in the model with nonconserved order
parameter, in spatial dimension and spin dimension .
We calculate, in the scaling limit, the exact short-distance singularities of
these correlation functions and compare these predictions to numerical
simulations. Our results suggest that the scaling hypothesis does not hold for
the model. Figures (23) are available on request - email
[email protected]: 23 pages, Plain LaTeX, M/C.TH.93/2
Цена политики адаптации к изменению климата
During the pre-industrial period the variation of Global Surface Air Temperature on 1 °C change Global Mean Sea Level on 24,79 m (SL 0). For the Global Warming period the rising rate of the Global Mean Sea Level will slowing down in 3,3 times simultaneously increases the Global Surface Air Temperature rate in 3,3 times. In the present time the Global Surface Air Temperature is 0,8 °C higher then pre-industrial level that will lead to the sea-level rise on 6 m. The EU Strategy on adaptation to climate change assume that the global warming must be limited to below 2 °C above pre-industrial level, that within some ages will lead to the sea-level rise on 15 m (15 times grater than for the A1B scenario, with the Sea-level rise up to 1 m). So in the future conditions the EU Strategy on adaptation to climate change do not assume rapid climate changes that will significantly increase the economic losses from Sea Level Rise.Вариация глобальной средней температуры Земли на 1 °С приводит к изменению уровня Мирового океана в эпоху доиндустриального развития на 24,79 м (SL 0). Для сценария глобального потепления климата Земли темп изменения уровня Мирового океана замедлится в 3,3 раза, что приведет к повышению скорости роста средней температуры Земли соответственно в 3,3 раза. В настоящее время средняя температура воздуха на планете превышает на 0,8 °С значение в эпоху доиндустриального развития, что может привести к повышению уровня Мирового океана на 6 м. Стратегия по адаптации к изменению климата Евросоюза предусматривает рост средней температура воздуха Земли на 2 °С, что в долгосрочной перспективе приведет к повышению уровня Мирового океана на 15 м, это в 15 раз превышает величину 1 м (сценарий A1B). Стратегия адаптации к изменению климата Евросоюза не предусматривает быстрых климатических изменений, что приведет к резкому увеличению экономических потерь от подъема уровня Мирового океана
Vortex annihilation in the ordering kinetics of the O(2) model
The vortex-vortex and vortex-antivortex correlation functions are determined
for the two-dimensional O(2) model undergoing phase ordering. We find
reasonably good agreement with simulation results for the vortex-vortex
correlation function where there is a short-scaled distance depletion zone due
to the repulsion of like-signed vortices. The vortex-antivortex correlation
function agrees well with simulation results for intermediate and long-scaled
distances. At short-scaled distances the simulations show a depletion zone not
seen in the theory.Comment: 28 pages, REVTeX, submitted to Phys. Rev.
Filtered screens and augmented Teichm\"uller space
We study a new bordification of the decorated Teichm\"uller space for a
multiply punctured surface F by a space of filtered screens on the surface that
arises from a natural elaboration of earlier work of McShane-Penner. We
identify necessary and sufficient conditions for paths in this space of
filtered screens to yield short curves having vanishing length in the
underlying surface F. As a result, an appropriate quotient of this space of
filtered screens on F yields a decorated augmented Teichm\"uller space which is
shown to admit a CW decomposition that naturally projects to the augmented
Teichm\"uller space by forgetting decorations and whose strata are indexed by a
new object termed partially oriented stratum graphs.Comment: Final version to appear in Geometriae Dedicat
Scaling Model of Annihilation-Diffusion Kinetics for Charged Particles with Long-Range Interactions
We propose the general scaling model for the diffusio n-annihilation reaction
with long-range power-law i
nteractions. The presented scaling arguments lead to the finding of three
different regimes, dep ending on the space dimensionality d and the long-range
force power e xponent n. The obtained kinetic phase diagram agrees well with
existing simulation data and approximate theoretical results.Comment: RevTEX, 7 pages, no figures, accepted to Physical Review
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