Inclusión de calix[4]areno en una matriz de sílice-titania: preparación, caracterización y aplicación como catalizador heterogéneo en epoxidación de alquenos

Se preparó una matriz mixta de sílice y titania con calix[4]areno incluido. Los calix[n]arenos son compuestos macrocíclicos integrados por n unidades fenólicas, unidas por grupos metileno en las posiciones 2 y

RICORS2040 : The need for collaborative research in chronic kidney disease

Chronic kidney disease (CKD) is a silent and poorly known killer. The current concept of CKD is relatively young and uptake by the public, physicians and health authorities is not widespread. Physicians still confuse CKD with chronic kidney insufficiency or failure. For the wider public and health authorities, CKD evokes kidney replacement therapy (KRT). In Spain, the prevalence of KRT is 0.13%. Thus health authorities may consider CKD a non-issue: very few persons eventually need KRT and, for those in whom kidneys fail, the problem is 'solved' by dialysis or kidney transplantation. However, KRT is the tip of the iceberg in the burden of CKD. The main burden of CKD is accelerated ageing and premature death. The cut-off points for kidney function and kidney damage indexes that define CKD also mark an increased risk for all-cause premature death. CKD is the most prevalent risk factor for lethal coronavirus disease 2019 (COVID-19) and the factor that most increases the risk of death in COVID-19, after old age. Men and women undergoing KRT still have an annual mortality that is 10- to 100-fold higher than similar-age peers, and life expectancy is shortened by ~40 years for young persons on dialysis and by 15 years for young persons with a functioning kidney graft. CKD is expected to become the fifth greatest global cause of death by 2040 and the second greatest cause of death in Spain before the end of the century, a time when one in four Spaniards will have CKD. However, by 2022, CKD will become the only top-15 global predicted cause of death that is not supported by a dedicated well-funded Centres for Biomedical Research (CIBER) network structure in Spain. Realizing the underestimation of the CKD burden of disease by health authorities, the Decade of the Kidney initiative for 2020-2030 was launched by the American Association of Kidney Patients and the European Kidney Health Alliance. Leading Spanish kidney researchers grouped in the kidney collaborative research network Red de Investigación Renal have now applied for the Redes de Investigación Cooperativa Orientadas a Resultados en Salud (RICORS) call for collaborative research in Spain with the support of the Spanish Society of Nephrology, Federación Nacional de Asociaciones para la Lucha Contra las Enfermedades del Riñón and ONT: RICORS2040 aims to prevent the dire predictions for the global 2040 burden of CKD from becoming true

GW190814: gravitational waves from the coalescence of a 23 solar mass black hole with a 2.6 solar mass compact object

We report the observation of a compact binary coalescence involving a 22.2–24.3 Me black hole and a compact object with a mass of 2.50–2.67 Me (all measurements quoted at the 90% credible level). The gravitational-wave signal, GW190814, was observed during LIGO’s and Virgo’s third observing run on 2019 August 14 at 21:10:39 UTC and has a signal-to-noise ratio of 25 in the three-detector network. The source was localized to 18.5 deg2 at a distance of - + 241 45 41 Mpc; no electromagnetic counterpart has been confirmed to date. The source has the most unequal mass ratio yet measured with gravitational waves, - + 0.112 0.009 0.008, and its secondary component is either the lightest black hole or the heaviest neutron star ever discovered in a double compact-object system. The dimensionless spin of the primary black hole is tightly constrained to �0.07. Tests of general relativity reveal no measurable deviations from the theory, and its prediction of higher-multipole emission is confirmed at high confidence. We estimate a merger rate density of 1–23 Gpc−3 yr−1 for the new class of binary coalescence sources that GW190814 represents. Astrophysical models predict that binaries with mass ratios similar to this event can form through several channels, but are unlikely to have formed in globular clusters. However, the combination of mass ratio, component masses, and the inferred merger rate for this event challenges all current models of the formation and mass distribution of compact-object binaries

Diferenças de gênero em relação a bens: a propriedade fundiária na América Latina Gender differences regarding assets: land property in Latin America

A diferença de gênero em relação à propriedade fundiária, na América Latina, é significativa. São poucos os países nos quais as mulheres constituem sequer um quarto dos proprietários. A desigualdade de gênero na posse de terras é relacionada à preferência masculina no momento da herança, ao privilégio masculino no casamento, ao viés masculino em programas comunitários e estatais de distribuição de terras, bem como ao viés de gênero no mercado fundiário, sendo que as mulheres têm menor probabilidade do que os homens de serem compradoras bem sucedidas. Mas também existem diferenças importantes por gênero na forma pela qual são adquiridas terras. A herança é o principal meio pelo qual a maioria das mulheres se torna proprietária, enquanto que os homens têm muito maior probabilidade do que as mulheres de adquirirem terras através da sua distribuição por comunidades ou pelo Estado, e por meio do mercado. São destacados os fatores que contribuem para uma tendência no sentido de maior igualdade de gênero na herança de terras e em programas públicos recentes.<br>Gender difference regarding land property in Latin America is significant. There are few countries in which women make up even a fourth of the owners. Gender inequality in land property is related to male preference at the moment of inheritance, to male privilege in marriage, to male bias in community and state land distribution programs as well as gender bias in the land market, women having less probability than men of being successful buyers. But there are also important gender differences in the way land is acquired. Inheritance is the main way by which women become owners, while men have much more probability to acquire land through their communities and the state as well as in the market. The article underlines the factors contributing to the tendency towards higher gender equality in land inheritance and recent state programs