65 research outputs found
Toistuvalla lannoituksella saatava kasvunlisäys kivennäismaiden männikÜissä ja kuusikoissa.
25 graphs, 11 tables80 ref. Summaries (En, Fi). Incl. 2 append. table
The effect of repeated nitrogen fertilization on the structure and development of the young pine and spruce stands.
Emergence of communities in weighted networks
Topology and weights are closely related in weighted complex networks and
this is reflected in their modular structure. We present a simple network model
where the weights are generated dynamically and they shape the developing
topology. By tuning a model parameter governing the importance of weights, the
resulting networks undergo a gradual structural transition from a module free
topology to one with communities. The model also reproduces many features of
large social networks, including the "weak links" property.Comment: 4 pages, 5 figure
Detecting modules in dense weighted networks with the Potts method
We address the problem of multiresolution module detection in dense weighted
networks, where the modular structure is encoded in the weights rather than
topology. We discuss a weighted version of the q-state Potts method, which was
originally introduced by Reichardt and Bornholdt. This weighted method can be
directly applied to dense networks. We discuss the dependence of the resolution
of the method on its tuning parameter and network properties, using sparse and
dense weighted networks with built-in modules as example cases. Finally, we
apply the method to data on stock price correlations, and show that the
resulting modules correspond well to known structural properties of this
correlation network.Comment: 14 pages, 6 figures. v2: 1 figure added, 1 reference added, minor
changes. v3: 3 references added, minor change
Forests for the New Millennium - MAKING FORESTS WORK FOR PEOPLE AND NATURE
THE WAYS IN WHICH FORESTS ARE PERCEIVED AND USED HAVE CHANGED DRAMATICALLY OVER RECENT YEARS. FORESTS ARE NO LONGER SEEN SIMPLY AS A SOURCE OF TIMBER, BUT AS COMPLEX ECOSYSTEMS WHICH SUSTAIN LIVELIHOODS AND PROVIDE A RANGE OF PRODUCTS AND ENVIRONMENTAL SERVICES. IT IS NOW WIDELY RECOGNISED THAT FORESTS CAN CONTRIBUTE TO RURAL DEVELOPMENT AND POVERTY ALLEVIATION.Forest, economics, livelihoods
Cyclical regulation of the insulin-like growth factor binding protein 3 gene in response to 1Îą,25-dihydroxyvitamin D3
The nuclear receptor vitamin D receptor (VDR) is known to associate with two vitamin D response element (VDRE) containing chromatin regions of the insulin-like growth factor binding protein 3 (IGFBP3) gene. In non-malignant MCF-10A human mammary cells, we show that the natural VDR ligand 1Îą,25-dihydroxyvitamin D3 (1Îą,25(OH)2D3) causes cyclical IGFBP3 mRNA accumulation with a periodicity of 60âmin, while in the presence of the potent VDR agonist Gemini the mRNA is continuously accumulated. Accordingly, VDR also showed cyclical ligand-dependent association with the chromatin regions of both VDREs. Histone deacetylases (HDACs) play an important role both in VDR signalling and in transcriptional cycling. From the 11 HDAC gene family members, only HDAC4 and HDAC6 are up-regulated in a cyclical fashion in response to 1Îą,25(OH)2D3, while even these two genes do not respond to Gemini. Interestingly, HDAC4 and HDAC6 proteins show cyclical VDR ligand-induced association with both VDRE regions of the IGFBP3 gene, which coincides with histone H4 deacetylation on these regions. Moreover, combined silencing of HDAC4 and HDAC6 abolishes the cycling of the IGFBP3 gene. We assume that due to more efficient VDR interaction, Gemini induces longer lasting chromatin activation and therefore no transcriptional cycling but monotonically increasing IGFBP3 mRNA. In conclusion, 1Îą,25(OH)2D3 regulates IGFBP3 transcription through short-term cyclical association of VDR, HDAC4 and HDAC6 to both VDRE-containing chromatin regions
Des ForĂŞts pour le Nouveau MillĂŠnaire - DES FORĂTS Ă GĂRER DANS LâINTĂRĂT DES GENS ET DE LA NATURE
LA FAĂON DONT LES FORĂTS SONT PERĂUES ET LEURS UTILISATIONS ONT BEAUCOUP CHANGĂ AU COURS DES DERNIĂRES ANNĂES. LES FORĂTS NE SONT PLUS CONSIDĂRĂES COMME ĂTANT UNIQUEMENT DES SOURCES DE BOIS MAIS DES ĂCOSYSTĂMES COMPLEXES QUI PERMETTENT Ă DES COMMUNAUTĂS DE SE DĂVELOPPER ET OFFRENT TOUTE UNE GAMME DE PRODUITS ET DE SERVICES ENVIRONNEMENTAUX. ON RECONNAĂT AUJOURDâHUI QUE LES FORĂTS PEUVENT CONTRIBUER AU DĂVELOPPEMENT RURAL ET Ă LA LUTTE CONTRE LA PAUVRETĂ.ForĂŞt, ĂŠconomie
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