7,258 research outputs found
La Garza Real en España. I. Población reproductora (1950-2000)
En este trabajo se analiza la evolución de la población reproductora de
Garza Real, Ardea cinerea, en España durante el período 1950-2000. El territorio
español se ha dividido en siete grandes zonas: Norte, Levante, y las cuencas de los
cinco grandes ríos (Guadalquivir, Guadiana, Tajo, Duero y Ebro). Los datos sobre
colonias y número de parejas nidificantes fueron obtenidos a partir de prospecciones
de los autores, de citas bibliográficas y de comunicaciones de organismos y personas
conocedoras de las colonias. Es probable que ya antes de 1950 hubiera colonias
ocupadas, pero se carece de datos publicados sobre ellas. En 1950 pudo haber
168 parejas reproductoras en 4 colonias, mientras que en 2000 hubo 4790 parejas
en 75 colonias. Las subpoblaciones de garza real asentadas de las cuencas del
Duero y Tajo parecen estar próximas al equilibrio numérico, mientras que las del
Ebro, Guadalquivir y Levante han aumentado notablemente su tamaño en la década
1990-2000. La cuenca del Guadiana contenía relativamente pocas parejas en el
período de estudio y en el Norte de España la población reproductora de la garza
real es aún poco significativa
Dynamic generation and attribution of revenues in a video platform
The consumption of online videos on the Internet grows every year, making it
a market that increasingly generates a greater volume of income. This paper
deals with a problem of great interest in this context: the allocation of the
generated revenues in a video website between the website and the video
creators. For this, we consider a dynamic model of the revenues generation. We
will consider that revenue can come from two sources: through the pay-per-view
system and through the insertion of advertisements in the videos. Then to study
how to divide the revenues in a reasonable and fair way between the two
parties, we consider a dynamic cooperative game that reflects the importance of
each part in generating revenue. From this game, we determine how its Shapley
value is and introduce other allocation rules derived from it. We provide a
structure of algorithm to calculate the Shapley value and its derived rules. We
show that the computational complexity of the algorithms is polynomial.
Finally, we provide some illustrative examples and simulations to illustrate
how the proposed allocation rules perform.Comment: 31 pages, 6 figure
Teranga Go!: Carpooling Collaborative Consumption Community with multi-criteria hesitant fuzzy linguistic term set opinions to build confidence and trust
Classic Delphi and Fuzzy Delphi methods are used to test content validity of
a data collection tools such as questionnaires. Fuzzy Delphi takes the opinion
issued by judges from a linguistic perspective reducing ambiguity in opinions
by using fuzzy numbers. We propose an extension named 2-Tuple Fuzzy Linguistic
Delphi method to deal with scenarios in which judges show different expertise
degrees by using fuzzy multigranular semantics of the linguistic terms and to
obtain intermediate and final results expressed by 2-tuple linguistic values.
The key idea of our proposal is to validate the full questionnaire by means of
the evaluation of its parts, defining the validity of each item as a Decision
Making problem. Taking the opinion of experts, we measure the degree of
consensus, the degree of consistency, and the linguistic score of each item, in
order to detect those items that affect, positively or negatively, the quality
of the instrument. Considering the real need to evaluate a b-learning
educational experience with a consensual questionnaire, we present a Decision
Making model for questionnaire validation that solve it. Additionally, we
contribute to this consensus reaching problem by developing an online tool
under GPL v3 license. The software visualizes the collective valuations for
each iteration and assists to determine which parts of the questionnaire should
be modified to reach a consensual solution.Comment: project at https://github.com/rosanamontes/teranga.go. arXiv admin
note: substantial text overlap with arXiv:2402.0177
Microenvironmental Snail1-induced immunosuppression promotes melanoma growth
Melanoma is an aggressive form of skin cancer due to its high metastatic abilities and resistance to therapies. Melanoma cells reside in a heterogeneous tumour icroenvironment that acts as a crucial regulator of its progression. Snail1 is an epithelial-tomesenchymal transition transcription factor expressed during development and reactivated in pathological situations including fibrosis and cancer. In this work, we show that Snail1 is activated in the melanoma microenvironment, particularly in fibroblasts.
Analysis of mouse models that allow stromal Snail1 depletion and therapeutic Snail1 blockade indicate that targeting Snail1 in the tumour microenvironment decreases melanoma growth and lung metastatic burden, extending mice survival. Transcriptomic
analysis of melanoma-associated fibroblasts and analysis of the tumours indicate that stromal Snail1 induces melanoma growth by promoting an immunosuppressive microenvironment and a decrease in anti-tumour immunity. This study unveils a novel role of Snail1 in melanoma biology and supports its potential as a therapeutic targe
Prescribed moorland burning meets good practice guidelines: A monitoring case study using aerial photography in the Peak District, UK
AbstractUpland moors in the UK have been managed for centuries using rotational prescribed-burning, but in recent years there has been contentious debate over its continuing use due to varying effects on moorland ecosystem services. Prescribed-burning should only be carried out using good-practice codes, which include restrictions on the size, location and frequency of burns. Good burning practice is an indicator of management standards and habitat condition in moorland landscapes. However, there has been little attempt to assess management performance with respect to these restrictions. We investigated prescribed-burning on a case-study estate (Howden Moor) in the Peak District National Park from 1988 to 2009 using management maps and aerial photography. The annual area burned (0.9%) was far below recommendations (10%) and patches were in keeping with the target sizes specified (mean±se: 2370±70 m2). The risk of a large or escaped fire was very low, with less than 1% of fires greater than 15,000m2. However, only 28.9% of the total burnable area was burned, leaving the rest unmanaged and accumulating fuel. Future guidelines might recommend the application of prescribed-burning across the range of Calluna vulgaris growth phases, to reduce fuel load and promote biodiversity at the landscape scale. We show that vegetation mapping and aerial photography are an effective method for monitoring prescribed-burning practice on moorlands. The information derived from such monitoring studies should lead to greater confidence in the standard of prescribed-burning and adherence to good-practice guidelines and requirements imposed by statutory authorities
Diachronism in the late Neoproterozoic–Cambrian arc-rift transition of North Gondwana: a comparison of Morocco and the Iberian Ossa-Morena Zone
In the northwestern border of the West African craton (North Gondwana), a transition from late Neoproterozoic
subduction/collision to Cambrian rift processes was recorded in the Anti-Atlas (Morocco) and in
the Ossa-Morena Zone (Iberia). Cambrian rifting affected both Pan-African and Cadomian basements in a
stepwise and diachronous way. Subsequently, both areas evolved into a syn-rift margin episodically
punctuated by uplift and tilting that precluded Furongian sedimentation. A comparison of sedimentary,
volcanic and geodynamic evolution is made in the late Neoproterozoic (Pan-African and Cadomian) belts
and Cambrian rifts trying to solve the apparent diachronous (SW–NE-trending) propagation of an early
Palaeozoic rifting regime that finally led to the opening of the Rheic Ocean
Retrieval of vegetation height in rice fields using polarimetric SAR interferometry with TanDEM-X data
This work presents for the first time a demonstration with satellite data of polarimetric SAR interferometry (PolInSAR) applied to the retrieval of vegetation height in rice fields. Three series of dual-pol interferometric SAR data acquired with large baselines (2–3 km) by the TanDEM-X system during its science phase (April–September 2015) are exploited. A novel inversion algorithm especially suited for rice fields cultivated in flooded soil is proposed and evaluated. The validation is carried out over three test sites located in geographically different areas: Sevilla (SW Spain), Valencia (E Spain), and Ipsala (W Turkey), in which different rice types are present. Results are obtained during the whole growth cycle and demonstrate that PolInSAR is useful to produce accurate height estimates (RMSE 10–20 cm) when plants are tall enough (taller than 25–40 cm), without relying on external reference information.This work has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO) and EU FEDER under project TIN2014-55413-C2-2-P. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement 606983, and the Land-SAF (the EUMETSAT Network of Satellite Application Facilities) project. The in-situ measurements in the Ipsala site were conducted with the funding of The Scientific and Technological Research Council of Turkey (TUBITAK, Project No.: 113Y446)
Tectonic evolution of Variscan Iberia: Gondwana–Laurussia
An integrated interpretation of the late Paleozoic structural and geochronological record of the Iberian Massif is
presented and discussed under the perspective of a Gondwana-Laurussia collision giving way to the Variscan
orogen. Compressional and extensional structures developed during the building of the Variscan orogenic crust
of Iberia are linked together into major tectonic events operating at lithosphere scale. A review of the
tectonometamorphic and magmatic evolution of the IberianMassif reveals backs and forths in the overall conver-
gence between Gondwana and Laurussia during theamalgamation of Pangea in late Paleozoic times. Stages dom-
inated by lithosphere compression are characterized by subduction, both oceanic and continental, development
of magmatic arcs, (over- and under-) thrusting of continental lithosphere, and folding. Variscan convergence re-
sulted in the eventual transference of a large allochthonous set of peri-Gondwanan terranes, the Iberian
Allochthon, onto the Gondwana mainland. The Iberian Allochthon bears the imprint of previous interaction be-
tween Gondwana and Laurussia, including their juxtaposition after the closure of the Rheic Ocean in Lower De-
vonian times. Stages governed by lithosphere extension are featured by the opening of two short-lived oceanic
basins that dissected previous Variscan orogenic crust, first in the Lower-Middle Devonian, following the closure
of the Rheic Ocean, and then in the early Carboniferous, following the emplacement of the peri-Gondwanan
allochthon. An additional, major intra-orogenic extensional event in the early-middle Carboniferous dismem-
bered the Iberian Allochthon into individual thrust stacks separated by extensional faults and domes. Lateral tec-
tonics played an important role through the Variscan orogenesis, especially during the creation of new tectonic
blocks separated by intracontinental strike-slip shear zones in the late stages of continental convergence
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