13,676 research outputs found
Approach to climatophilous vegetation series of Serra da Estrela (Portugal)
This work contains the study results of climatophilous vegetation series from Serra da Estrela, the highest
mountain on the Portuguese mainland. Located in central-northern Portugal in the Estrelensean Sector (Carpetan-Leonese
Subprovince), the Serra da Estrela has several bioclimatic stages, mainly resulting from slope and altitude ranges:
mesomediterranean, submediterranean mesotemperate, supramediterranean, submediterranean supratemperate, and submediterranean
orotemperate. In each of these belts are observed changes in plant communities that determine variations
in terms of the vegetation series. The methodology was based on Dynamic-Catenal Phytosociology. The results show the
presence of five climatophilous series; their structural characteristics and dynamics are described in this paper: 1.
Lycopodio clavati–Junipereto nani S.; 2. Saxifrago spathularis–Betuleto celtibericae S.; 3. Holco mollis–Querco
pyrenaicae S.; 4. Arbuto–Querco pyrenaicae cytisetoso grandiflori S.; e 5. Viburno tini–Querco roboris S
Effective Theories for 2+1 Dimensional Non-Abelian Topological Spin Liquids
In this work we propose an effective low-energy theory for a large class of
2+1 dimensional non-Abelian topological spin liquids whose edge states are
conformal degrees of freedom with central charges corresponding to the coset
structure . For particular values of
it furnishes the series for unitary minimal and superconformal models.
These gapped phases were recently suggested to be obtained from an array of
one-dimensional coupled quantum wires. In doing so we provide an explicit
relationship between two distinct approaches: quantum wires and Chern-Simons
bulk theory. We firstly make a direct connection between the interacting
quantum wires and the corresponding conformal field theory at the edges, which
turns out to be given in terms of chiral gauged WZW models. Relying on the
bulk-edge correspondence we are able to construct the underlying non-Abelian
Chern-Simons effective field theory.Comment: 41 pages, 5 figures, typos corrected, references added, published
versio
Comparing the Productive Efficiency of Cooperatives and Private Enterprises: The Portuguese Wine Industry as a Case Study
This paper compares the efficiency of cooperatives and private enterprises in the Portuguese wine industry, employing data envelopment analysis (DEA). The use of DEA for the analysis of comparative efficiency within a sector is a key tool in evaluating organizational competitiveness. Competitiveness should be based on benchmarking the different types of organizations that comprise the viniculture sector. We conclude that Portuguese wine cooperatives, on average, are more efficient than their private counterparts. Economic implications arising from the study are discussed.cooperatives, private enterprises, technical efficiency, DEA, wine industry, Portugal, Agribusiness,
New Proposals on Portuguese Vegetation (II)
As a consequence of the geobotanical studies that have been developed in west and southern areas of the Iberian Peninsula,
four new phytosociological associations are proposed, integrated in the perennial mesophytic grasslands of Stipo
giganteae-Agrostietea castellanae (Serratulo flavescentis-Celticetum giganteae, Armerio macrophyllae-Celticetum giganteae,
Centaureo rothmaleranae-Celticetum giganteae, and Centaureo coutinhoi-Dactyletum lusitanici). For each proposed
unit, besides its syntaxonomical fitting, we present its ecological diagnosis and the serial and catenal context, as well as
its patrimonial value
Suitable methods for landscape evaluation and valorization: the third dimension in landscape metrics
Landscape metrics have been widely developed over the last two decades. One of the major recent developments
in landscape metrics analysis was the integration of the third dimension. Topography has an extremely important
role in ecosystems function and structure, even though the common analysis in landscape ecology only considers a planimetric
surface, which leads to some erroneous results particularly in mountain areas. In this study we tested landscape
metrics behaviour in 13 sample areas of 10,000 m2 each in several topographical conditions of Central Alentejo, Portugal.
The significance analysis of the results achieved in planimetric and three-dimensional environments is presented
- …