18,006 research outputs found
Differential photosynthetic adaptation between size-classes of Spruce and Fir juveniles help to explain the co-existence of the two species.
Background/Question/Methods 
_Abies sachalinensis_ (Sakhalin Fir) and _Picea glehnii_ (Glehn’s Spruce) are major components of the sub-boreal forests of Hokkaido, Japan. Similar Spruce-Fir forests can be found in many other places in the northern hemisphere and will probably be impacted by global warming. Therefore, detailed knowledge of these species’ physiology and life-history strategies at different growth stages is important to understand present communities and to support reliable prediction of possible consequences of global climate change. 
Accordingly, the objective of this study was to establish relations between community dynamics, life-history strategies and photosynthetic adaptation of these species, on different developmental stages. 
The study is taking place on a sub-boreal forest plot in north Japan (N 44º 19’, E 142º 15’). Twenty shade-growing individuals of both species were divided into two height classes: seedlings, if height < 50cm; and saplings, if height > 100cm. The canopy coverage over each individual was assessed by analyzing hemispherical photography and average light incidence. Leaf pigments are being analyzed by chromatography. Light response curves and chlorophyll fluorescence are being measured seasonally, except in winter. Results are analyzed through General Linear Models. The study period was from spring 2009 to summer 2010. 
Results/Conclusions 
Results show an inversion of the photosynthetic adaptation between seedlings and saplings, and also between species. _Picea_ seedlings and _Abies_ saplings have greater total chlorophyll content and higher photosynthetic rates than _Picea_ saplings and _Abies_ seedlings. As a consequence, the superior competitor between similar sized individuals of both species appears to change between size-classes, with _Abies_ presenting higher photosynthetic rates at the sapling class and _Picea_ at the seedling class. Nevertheless, no significant growth has been observed in any of the groups until now. Results also disagree with some of the previously reported photosynthetic characteristics of these species, with _Picea_ seedlings displaying more traits usually associated with shade adaptation than _Abies_ seedlings.

The scaling limit of the incipient infinite cluster in high-dimensional percolation. II. Integrated super-Brownian excursion
For independent nearest-neighbour bond percolation on Z^d with d >> 6, we
prove that the incipient infinite cluster's two-point function and three-point
function converge to those of integrated super-Brownian excursion (ISE) in the
scaling limit. The proof is based on an extension of the new expansion for
percolation derived in a previous paper, and involves treating the magnetic
field as a complex variable. A special case of our result for the two-point
function implies that the probability that the cluster of the origin consists
of n sites, at the critical point, is given by a multiple of n^{-3/2}, plus an
error term of order n^{-3/2-\epsilon} with \epsilon >0. This is a strong
statement that the critical exponent delta is given by delta =2.Comment: 56 pages, 3 Postscript figures, in AMS-LaTeX, with graphicx, epic,
and xr package
Pendekatan-Pendekatan dalam Studi Demokrasi di Asia Tenggara dan Relevansinya untuk Indonesia
Democratization in Southeast Asian countries is often perceived as transforming the countries into a kind of Western liberal democracy. By using Indonesian case, this paper, however, shows that this perception does not reflect current complexities in political arena. The transition to democracy in Indonesia has both the elements of modern and traditional political cultures and institutions. The paper suggests that democratization is better seen from the process of adaptation and hybridization of the modenrn and traditional aspects of Indonesian politics
Anomalous Crossing Frequency in Odd Proton Nuclei
A generic explanation for the recently observed anomalous crossing
frequencies in odd proton rare earth nuclei is given. As an example, the proton
band in Ta is discussed in detail by using the
angular momentum projection theory. It is shown that the quadrupole pairing
interaction is decisive in delaying the crossing point and the changes in
crossing frequency along the isotope chain are due to the different neutron
shell fillings
On the Backbending Mechanism of Cr
The mechanism of backbending in Cr is investigated in terms of the
Projected Shell Model and the Generator Coordinate Method. It is shown that
both methods are reasonable shell model truncation schemes. These two quite
different quantum mechanical approaches lead to a similar conclusion that the
backbending is due to a band crossing involving an excited band which is built
on simultaneously broken neutron and proton pairs in the ``intruder'' subshell
. It is pointed out that this type of band crossing is usually known
to cause the second backbending in rare-earth nuclei.Comment: 4 pages, 4 figures, accepted for publication in Phys. Rev. Let
New Lower Bounds on the Self-Avoiding-Walk Connective Constant
We give an elementary new method for obtaining rigorous lower bounds on the
connective constant for self-avoiding walks on the hypercubic lattice .
The method is based on loop erasure and restoration, and does not require exact
enumeration data. Our bounds are best for high , and in fact agree with the
first four terms of the expansion for the connective constant. The bounds
are the best to date for dimensions , but do not produce good results
in two dimensions. For , respectively, our lower bound is within
2.4\%, 0.43\%, 0.12\%, 0.044\% of the value estimated by series extrapolation.Comment: 35 pages, 388480 bytes Postscript, NYU-TH-93/02/0
Transition region features observed with Hinode/EIS
Two types of active region feature prominent at transition region
temperatures are identified in Hinode/EIS data of AR 10938 taken on 2007
January 20. The footpoints of 1 MK TRACE loops are shown to emit strongly in
emission lines formed at log T=5.4-5.8, allowing the temperature increase along
the footpoints to be clearly seen. A density diagnostic of Mg VII yields the
density in the footpoints, with one loop showing a decrease from 3x10^9 cm^-3
at the base to 1.5x10^9 cm^-3 at a projected height of 20 Mm. The second
feature is a compact active region transition region brightening which is
particularly intense in O V emission (log T=5.4) but also has a signature at
temperatures up to log T=6.3. The Mg VII diagnostic gives a density of 4x10^10
cm^-3, and emission lines of Mg VI and Mg VII show line profiles broadened by
50 km/s and wings extending beyond 200 km/s. Continuum emission in the short
wavelength band is also found to be enhanced, and is suggested to be free-bound
emission from recombination onto He^+.Comment: 11 pages, 9 figures, submitted to PASJ Hinode first results issu
Vertex operators for quantum groups and application to integrable systems
Starting with any R-matrix with spectral parameter, obeying the Yang-Baxter
equation and a unitarity condition, we construct the corresponding infinite
dimensional quantum group U_{R} in term of a deformed oscillators algebra A_R.
The realization we present is an infinite series, very similar to a vertex
operator.
Then, considering the integrable hierarchy naturally associated to A_{R}, we
show that U_{R} provides its integrals of motion. The construction can be
applied to any infinite dimensional quantum group, e.g. Yangians or elliptic
quantum groups.
Taking as an example the R-matrix of Y(N), the Yangian based on gl(N), we
recover by this construction the nonlinear Schrodinger equation and its Y(N)
symmetry.Comment: 19 pages, no figure, Latex2e Error in theorem 3.3 and lemma 3.1
correcte
EUV emission lines and diagnostics observed with Hinode/EIS
Quiet Sun and active region spectra from the Hinode/EIS instrument are
presented, and the strongest lines from different temperature regions
discussed. A list of emission lines recommended to be included in EIS
observation studies is presented based on analysis of blending and diagnostic
potential using the CHIANTI atomic database. In addition we identify the most
useful density diagnostics from the ions covered by EIS.Comment: 14 pages, 3 figures, submitted to PASJ Hinode first results issu
Scaling of Self-Avoiding Walks in High Dimensions
We examine self-avoiding walks in dimensions 4 to 8 using high-precision
Monte-Carlo simulations up to length N=16384, providing the first such results
in dimensions on which we concentrate our analysis. We analyse the
scaling behaviour of the partition function and the statistics of
nearest-neighbour contacts, as well as the average geometric size of the walks,
and compare our results to -expansions and to excellent rigorous bounds
that exist. In particular, we obtain precise values for the connective
constants, , , ,
and give a revised estimate of . All of
these are by at least one order of magnitude more accurate than those
previously given (from other approaches in and all approaches in ).
Our results are consistent with most theoretical predictions, though in
we find clear evidence of anomalous -corrections for the scaling of
the geometric size of the walks, which we understand as a non-analytic
correction to scaling of the general form (not present in pure
Gaussian random walks).Comment: 14 pages, 2 figure
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