5,688 research outputs found
Bioclimatology, structure, and conservation perspectives of Quercus pyrenaica, Acer opalus subsp. Granatensis, and Corylus avellana deciduous forests on Mediterranean bioclimate in the South-Central part of the Iberian Peninsula
The plant variability in the southern Iberian Peninsula consists of around 3500 different taxa due to its high bioclimatic, geographic, and geological diversity. The deciduous forests in the southern Iberian Peninsula are located in regions with topographies and specific bioclimatic conditions that allow for the survival of taxa that are typical of cooler and wetter bioclimatic regions and therefore represent the relict evidence of colder and more humid paleoclimatic conditions. The floristic composition of 421 samples of deciduous forests in the south-central part of the Iberian Peninsula were analyzed. The ecological importance index (IVI) was calculated, where the most important tree species were Quercuspyrenaica, Aceropalus subsp. Granatensis, and Corylusavellana. These species are uncommon in the south-central part of the Iberian Peninsula, forming forests of little extension. An analysis of the vertical distribution of the species (stratum) shows that the majority of the species of stratum 3 (hemicriptophics, camephytes, geophites, and nanophanerophytes) are characteristic of deciduous forests, and their presence is positively correlated with high values of bioclimatic variables related to humidity and presence of water in the soil (nemoral environments), while they are negatively correlated with high values of bioclimatic variables related to high temperatures, evapotranspiration, and aridity. This work demonstrates that several characteristic deciduous forest taxa are more vulnerable to disappearance due to the loss of their nemoral conditions caused by gaps in the tree or shrub canopy. These gaps lead to an increase in evapotranspiration, excess insolation, and a consequent loss of water and humidity in the microclimatic conditions.info:eu-repo/semantics/publishedVersio
Hubble drift in Palatini f(R) theories
In a Palatini f(R) model, we define chronodynamical effects due to the choice of atomic clocks as standard reference clocks and we develop a formalism able to quantitatively separate them from the usual effective dark sources one has in extended theories, namely the ones obtained by recasting field equations for g˜ in the form of Einstein equations. We apply the formalism to Hubble drift and briefly discuss the issue about the physical frame. In particular, we shall argue that there is not one single physical frame, for example, in the sense one defines measure in one frame while test particles goes along geodesics in the other frame. That is the physical characteristic of extended gravity. As an example, we discuss how the Jordan frame may be well suited to discuss cosmology, though it fails within the solar system. © 2019, Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature
Why Silver Deposition is so Fast: Solving the Enigma of Metal Deposition
A perfect match: Silver deposition is one of the fastest electrochemical reactions, even though the Ag+ ion loses more than 5 eV solvation energy in the process. This phenomenon, an example of the enigma of metal deposition, was investigated by a combination of MD simulations, DFT, and specially developed theory. At the surface, the Ag+ ion experiences a strong interaction with the sp band of silver, which catalyzes the reaction.Fil: Pinto, Leandro M. C.. Universidade Estadual Paulista Julio de Mesquita Filho. Facultad de Filosofia E Ciencias-campus de Marilia; Brasil. Universitat Ulm; AlemaniaFil: Spohr, Eckhard. Universitat Duisburg - Essen; AlemaniaFil: Quaino, Paola Monica. Universidad Nacional del Litoral. Facultad de IngenierÃa QuÃmica. Programa de ElectroquÃmica Aplicada E IngenierÃa ElectroquÃmica; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Santa Fe; ArgentinaFil: Santos, Elizabeth del Carmen. Universitat Ulm; Alemania. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Córdoba. Instituto de FÃsica "Enrique Gaviola"; ArgentinaFil: Schmickler, Wolfgang. Institute Of Theoretical Chemistry; Alemania. Universitat Ulm; Alemani
Biased news sharing and partisan polarization on social media
In the ever-connected digital landscape, news dissemination on social media
platforms serves as a vital source of information for the public. However, this
flow of information is far from unbiased. It is deeply influenced by the
political inclinations of the users who share news as well as the inherent
biases present in the news outlets themselves. These biases in news consumption
play a significant role in the creation of echo chambers and the reinforcement
of beliefs. This phenomenon, in turn, influences the voting intentions of the
population during critical electoral periods. In this study, we use a metric
called "Sentiment Bias", a tool designed to classify news outlets according to
their biases. We explore the impact of this metric on various levels, ranging
from news outlets to individual user biases. Our metric, while simple, unveils
a well-known trend: users prefer news aligning with their political beliefs.
Its power lies in extending this insight to specific topics. Users consistently
share articles related to subjects that echo their favored candidates,
illuminating a deeper layer of political alignment in online discourse
Evaluación de Competencias: un Caso práctico en Materias de QuÃmica de Titulaciones de IngenierÃa
Interesante caso práctic
The hidden dimension of information diffusion: A latent space representation of Social Media News Sharing behavior
In times marked by an abundance of news sources and the widespread use of
social media for staying informed, acquiring accurate data faces increasing
challenges. Today, access to information plays a crucial role in shaping public
opinion and is significantly influenced by interactions on social media.
Therefore, studying the dissemination of news on these platforms is vital for
understanding how individuals stay informed. In this paper, we study emergent
properties of media outlet sharing behavior by users in social media. We
quantify this behavior in terms of coordinates in a latent space proposing a
metric called Media Sharing Index (MSI). We observe that the MSI shows a
bimodal distribution in this latent dimension, reflecting the preference of
large groups of users for specific groups of media outlets. This methodology
allows the study of the extent to which communities of interacting users are
permeable to different sources of information. Additionally, it facilitates the
analysis of the relationship between users' media outlet preferences, their
political leanings, and the political leanings of the media outlets
Uso de los tra amientos termico e no termico (alta presion hidrostatica) para la inactivación de enzimas bacterianas metaloproteases presentes en la degradación de leche.
El estudio de la aplicación de la tecnologÃa de alta presión en el tratamiento de la leche para la inactivación de las enzimas proteolÃticas puede proporcionar un producto con alta calidad y salubridad diferencial, capaz de investir en un aumento del consumo y de valor agregado, con el fin de beneficiarse de la cadena de producción, con impactos económicos y sociales
Extended cosmology in Palatini f (R)-theories
Abstract. We consider the cosmological models based on Palatini f (R)-theory for the function f (R) = αR − 2 β R2 − 3R γ , which, when only dust visible matter is considered, is called dune cosmology in view of the shape of the function f (R(a)) (being a the scale factor). We discuss the meaning of solving the model, and interpret it according to the Ehlers-Pirani-Schild framework as defining a Weyl geometry on spacetime. Accordingly, we extend the definitions of luminosity distance, proper distance, and red-shift to Weyl geometries and fit the values of parameters to SNIa data. Since the theoretical prediction is model-dependent, we argue that the fit is affected by an extra choice, namely a model for atomic clocks, which, in principle, produces observable effects. To the best of our knowledge, these effects have not being considered in the literature before
Periodontitis and Hypertension: Is the Association Causal?
High blood pressure (BP) and periodontitis are two highly prevalent conditions worldwide with a significant impact on cardiovascular disease (CVD) complications. Poor periodontal health is associated with increased prevalence of hypertension and may have an influence on BP control. Risk factors such as older age, male gender, non-Caucasian ethnicity, smoking, overweight/obesity, diabetes, low socioeconomic status, and poor education have been considered the common denominators underpinning this relationship. However, recent evidence indicates that the association between periodontitis and hypertension is independent of common risk factors and may in fact be causal in nature. Low-grade systemic inflammation and redox imbalance, in particular, represent the major underlying mechanisms in this relationship. Neutrophil dysfunction, imbalance in T cell subtypes, oral-gut dysbiosis, hyperexpression of proinflammatory genes, and increased sympathetic outflow are some of the pathogenetic events involved. In addition, novel findings indicate that common genetic bases might shape the immune profile towards this clinical phenotype, offering a rationale for potential therapeutic and prevention strategies of public health interest. This review summarizes recent advances, knowledge gaps and possible future directions in the field
- …