Exponential instability in the fractional Calder\'on problem

In this note we prove the exponential instability of the fractional Calder\'on problem and thus prove the optimality of the logarithmic stability estimate from \cite{RS17}. In order to infer this result, we follow the strategy introduced by Mandache in \cite{M01} for the standard Calder\'on problem. Here we exploit a close relation between the fractional Calder\'on problem and the classical Poisson operator. Moreover, using the construction of a suitable orthonormal basis, we also prove (almost) optimality of the Runge approximation result for the fractional Laplacian, which was derived in \cite{RS17}. Finally, in one dimension, we show a close relation between the fractional Calder\'on problem and the truncated Hilbert transform.Comment: 17 page

Soft power: Power of attraction or confusion?

Despite its popularity soft power remains power of confusion. The paper examines the concept, with a special focus on the nature and sources of soft power. Nye’s notion of soft power is largely ethnocentric and based on the assumption that there is a link between attractiveness and the ability to influence others in international relations. This poses two problems: Firstly, a country has many different actors. Some of them like the attraction and others don’t. Whether the attraction will lead to the ability to influence the policy of the target country depends on which groups in that country find it attractive and how much control they have on policymaking. Secondly, policymaking at the state level is far more complicated than at the personal level; and has different dynamics that emphasise the rational considerations. This leaves little room for emotional elements thus significantly reducing the effect of soft power. Given the nature of soft power being uncontrollable and unpredictable, it would be impossible to wield soft power in any organised and coordinated fashion as Nye suggested. Furthermore, the relationship between two countries is shaped by many complex factors. It is ultimately decided by the geopolitics and strategic interests of nations, in which soft power may play only a limited role. The paper also discusses the link between soft power and nation branding as both concepts are concerned with a nation’s influence on the world stage. Public diplomacy is a subset of nation branding that focuses on the political brand of a nation; whereas nation branding is about how a nation as whole to reshape the international opinions. A successful nation branding campaign will help create a more favourable and lasting image among the international audience thus further enhancing a country’s soft power

La participación ciudadana juvenil en el estado de México. Una aproximación desde las perspectivas de la movilización y la dependencia de recursos

The issue of the downward trend in civic engagement has been part of the public and governmental agendas of several Latin-American countries, including Mexico. Scholars andcommentators have expressed profound concern not only regarding the overall low levels of citizen participation and political activism, but, especially among young people. Particularly worrying is the trend of increasing passiveness and reluctance among youth to participate in politics and exercise their right to vote. However, such manifestations of political disaffection are, perhaps, expressive forms of the capacity to condition and, possibly, to mobilize one of the main resources that young people have, their participation. In this vein, the lack of trust in traditional political institutions seems to be one of the main factors restraining young people engagement in the political and democratic process.El tema de la baja participación ciudadana ha estado en las agendas pública y gubernamental de la mayoría de los países de la región latinoamericana, incluyendo a México. Especialistas y comentadores han expresado una profunda preocupación, no solo respecto a los bajos niveles de participación ciudadana y activismo político entre la población en general, sino especialmente entre los jóvenes. Considerando al Estado de México, particularmente preocupante es la creciente tendencia de pasividad y resistencia entre la gente joven para participar en políticay/o procesos político-electorales. No obstante, dichas manifestaciones de desafección política son, tal vez, formas expresivas de la capacidad de condicionar y, posiblemente, movilizar uno de los principales recursos que tienen los y las jóvenes, y que es su participación. Ello a la vez sugiere una agenda de investigación pendiente en los estudios sobre juventud y particularmente respecto a la participación juvenil

Reúso de aguas residuales: impacto en los atributos químicos y macronutricionales en un suelo inceptisol irrigado con aguas residuales domésticas tratadas

(Eng) This study aimed to estimate the potential impact of wastewater reuse on the chemical and macronutritional attributes of an inceptisol cropped with sugarcane. The experimental design was in three randomized blocks, in split-plot design (three replicates per treatment), with three different irrigation treatments: treated wastewater (TWW) from Cañaveralejo wastewater treatment plant (WWTP-C); groundwater without any fertilizer (GW); and groundwater with chemical fertilizer (GW+CF). At the end of the study, plots with treated wastewater irrigation improved slightly Ca/Mg, Mg/K, and Ca+Mg/K ratios, increased OM, Na, P, and K contents and decreased pronouncedly inorganic nitrogen (N-NH4, N-NO3) of an inceptisol. Besides, we found that the type of treatment did not influence the variation of chemical attributes in soil, since statistically differences were no found in comparison among treatments. Therefore, our results suggest no adverse impact on chemical soil attributes due to wastewater reuse on sugarcane irrigation.(Spa) Este estudio tuvo como objetivo estimar el potencial impacto en los atributos químicos y macronutricionales de un suelo inceptisol sembrado con caña de azúcar y sometido a tres diferentes tratamientos de riego: Efluente de la PTAR-C (T1), Agua de Pozo (T2) y Agua de Pozo más fertilización química (T3). Se instaló un experimento en bloques completos al alzar con parcelas divididas con tres repeticiones. Al final del estudio se encontró que las relaciones de bases químicas (Ca/Mg, Mg/K, Ca+Mg/K) mejoraron en todas las parcelas, en todos los tratamientos, situación que se ratifica al no encontrarse diferencias estadísticas significativas entre los tratamientos. Así mismo, se encontró que el tipo de tratamiento no influyó en la variación en los contenidos de los macronutrientes (N, P, K) del suelo. Los contenidos de materia orgánica, P, Na y K aumentaron; y disminuyeron los de nitrógeno inorgánico (N-NH4, N-NO3) independientemente del tratamiento, lo que permite inferir la no asociación de impactos adversos en el suelo por el reúso de agua residual tratada en riego de caña de azúcar

An instance of Neanderthal mobility dynamics: a lithological approach to the flint assemblage from stratigraphic unit VIII of El Salt rockshelter (Alcoi, eastern Iberia)

The relationship between hunter-gatherer group mobility and lithic raw material procurement strategies is central to the study of Neanderthal productive behaviours. In this framework, determination of flint procurement sources through lithological analysis is key to infer Neanderthal group mobility patterns. El Salt rockshelter (Alcoi, Alacant, eastern Iberia) features different nearby flint sources, including primary outcrops and secondary deposits containing flint. In this study, we sourced the stratigraphic unit viii archaeological flint assemblage based on identification of geogenic and postgenetic lithological traits. Our results indicate that flint procurement at El Salt during the stratigraphic unit viii Neanderthal occupations was mainly linked to Pleistocene secondary deposits along the upper and middle courses of Serpis river. The artefacts were made predominantly on alluvially reworked nodules of different flint types. Connecting these procurement areas with their corresponding knapping products reveals a direct relationship between flint-source distance and degree of technical intervention, and defines a hypothetically unidirectional series of rivershore itineraries of procurement.This work has been accomplished during the valid period of the research project titled Clima e interacciones humanas en el Mediterráneo central ibérico durante el MIS 4 (IBEMIS4), granted by the Spanish central government (PID2019-107113RB-I00). The first author (AM) is funded by Universitat d’Alacant through a university faculty formation grant (UAFPU2018-049). The second (SSR) and the fourth (LP) are funded by the Valencian autonomous government through a predoctoral research-staff contracting grant (ACIF/2021/407) and a postdoctoral research-staff contracting grant (APOSTD/2020/202), respectively

Tubulin nitration in human gliomas

Immunohistochem. and biochem. investigations showed that significant protein nitration occurs in human gliomas, esp. in grade IV glioblastomas at the level of astrocytes and oligodendrocytes and neurons. Enhanced alpha-tubulin immunoreactivity was co-present in the same elements in the glioblastomas. Proteomic methodologies were employed to identify a nitrated protein band at 55 kDa as alpha-tubulin. Peptide mass fingerprinting procedures demonstrated that tubulin is nitrated at Tyr224 in grade IV tumor samples but is unmodified in grade I samples and in non-cancerous brain tissue. These results provide the first characterization of endogenously nitrated tubulin from human tumor samples

A Contribution to the estimation of binary halide and pseudo-halide equilibrium constants using a linear extrapolation methodology

The molar single ion activity coefficient (yF) of fluoride ions was determined at 25 °C and ionic strengths between 0.100 and 3.00 mol L-1 NaClO4 using an ion-selective electrode. The activity coefficient dependency on ionic strength was determined to be ΦF = log yF = 0.2315I - 0.041I². The function ΦF(I), combined with functions obtained in previous work for copper (ΦCu) and hydrogen (ΦH), allowed us to make the estimation of the stoichiometric and thermodynamic protonation constants of some halides and pseudo-halides as well as the formation constants of some pseudo-halides and fluoride 1:1 bivalent cation complexes. The calculation procedure proposed in this paper is consistent with critically-selected experimental data. It was demonstrated that it is possible to use ΦF(I) for predicting the thermodynamic equilibrium parameters independently of Pearson's hardness of acids and bases.O coeficiente de atividade molar individual do íon fluoreto (yF) foi determinado a 25° C para valores de força iônica entre 0,100 and 3,00 mol L-1 (NaClO4) usando-se um eletrodo íon-seletivo. A dependência do coeficiente de atividade com a força iônica é explicada pela equação ΦF = log yF = 0,2315I - 0,041I². A função ΦF(I), foi associada a outras funções estimadas em trabalhos anteriores, por exemplo,ΦCu(I) para cobre, e ΦH(I) para íon hidrogênio, possibilitando a estimativa de constantes de estabilidade estequiométricas e termodinâmicas tanto para equilíbrios de protonação de alguns haletos e pseudo-haletos como para as constantes de formação de complexos 1:1 de metais bivalentes com fluoreto e pseudo-haletos. O procedimento de cálculo proposto é consistente com dados experimentais criticamente selecionados da literatura. Verificou-se que é possível usar ΦF(I) na previsão de parâmetros de equilíbrio termodinâmicos independentemente do caráter HSAB de Pearson .135141Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES