One-Electron Singular Branch Lines of the Hubbard Chain

The momentum and energy dependence of the weight distribution in the vicinity of the one-electron spectral-function singular branch lines of the 1D Hubbard model is studied for all values of the electronic density and on-site repulsion $U$. To achieve this goal we use the recently introduced pseudofermion dynamical theory. Our predictions agree quantitatively for the whole momentum and energy bandwidth with the peak dispersions observed by angle-resolved photoelectron spectroscopy in the quasi-1D organic conductor TTF-TCNQ.Comment: Replaced with shortened version; 4 figure

The Low-Energy Limiting Behavior of the Pseudofermion Dynamical Theory

In this paper we show that the general finite-energy spectral-function expressions provided by the pseudofermion dynamical theory for the one-dimensional Hubbard model lead to the expected low-energy Tomonaga-Luttinger liquid correlation function expressions. Moreover, we use the former general expressions to derive correlation-function asymptotic expansions in space and time which go beyond those obtained by conformal-field theory and bosonization: we derive explicit expressions for the pre-factors of all terms of such expansions and find that they have an universal form, as the corresponding critical exponents. Our results refer to all finite values of the on-site repulsion U and to a chain of length L very large and with periodic boundary conditions for the above model, but are of general nature for many integrable interacting models. The studies of this paper clarify the relation of the low-energy Tomonaga-Luttinger liquid behavior to the scattering mechanisms which control the spectral properties at all energy scales and provide a broader understanding of the unusual properties of quasi-one-dimensional nanostructures, organic conductors, and optical lattices of ultracold fermionic atoms. Furthermore, our results reveal the microscopic mechanisms which are behind the similarities and differences of the low-energy and finite-energy spectral properties of the model metallic phas

Psychologist’s role in a Psychogeriatric Day Care Center

[Resumen] La progresiva implantación de centros asistenciales para la tercera edad, junto con la interdisciplinareidad de la actuación en valoración y posterior actuación frente a la persona mayor, hacen que el psicólogo desempeñe un papel claramente definido, y que en lo que respecta a los Centros de día psicogeriátricos, papel más importante si cabe, por las características del usuario, cada vez se beneficia más de una actuación altamente cualificada. Mediante el presente trabajo pretendemos realizar una descripción de las distintas funciones del psicólogo en un Centro de día específico para pacientes con demencia, revisando y proponiendo las diferentes actuaciones de acuerdo a sus áreas de investigación.[Abstract] The progressive establishment of assistant centers for the third age, together with the interdisciplinary of the performance in the valuation and later performance dealing with the elderly people, make psychologist plays a clearly defined part, and in what concerns to the Psychogeriatric Day Care centers, a more important role, if possible for the user’s characteristics that benefits more and more of a highly qualified performance. By means of the present work we seek to carry out a description of the psychologist’s different functions in a day care center, specific for Alzheimer’s disease patients, revising and proposing the different performances according to the intervention areas

Magnetic Properties of Weakly Doped Antiferromagnets

We study the spin excitations and the transverse susceptibility of a two-dimensional antiferromagnet doped with a small concentration of holes in the t-J model. The motion of holes generates a renormalization of the magnetic properties. The Green's functions are calculated in the self-consistent Born approximation. It is shown that the long-wavelength spin waves are significantly softened and the shorter-wavelength spin waves become strongly damped as the doping increases. The spin wave velocity is reduced by the coherent motion of holes, and not increased as has been claimed elsewhere. The transverse susceptibility is found to increase considerably with doping, also as a result of coherent hole motion. Our results are in agreement with experimental data for the doped copper oxide superconductors.Comment: 20 page

Electronic structure of the quasi-one-dimensional organic conductor TTF-TCNQ

We study the electronic structure of the quasi-one-dimensional organic conductor TTF-TCNQ by means of density-functional band theory, Hubbard model calculations, and angle-resolved photoelectron spectroscopy (ARPES). The experimental spectra reveal significant quantitative and qualitative discrepancies to band theory. We demonstrate that the dispersive behavior as well as the temperature-dependence of the spectra can be consistently explained by the finite-energy physics of the one-dimensional Hubbard model at metallic doping. The model description can even be made quantitative, if one accounts for an enhanced hopping integral at the surface, most likely caused by a relaxation of the topmost molecular layer. Within this interpretation the ARPES data provide spectroscopic evidence for the existence of spin-charge separation on an energy scale of the conduction band width. The failure of the one-dimensional Hubbard model for the {\it low-energy} spectral behavior is attributed to interchain coupling and the additional effect of electron-phonon interaction.Comment: 18 pages, 9 figure

A horizon scan exercise for aquatic invasive alien species in Iberian inland waters

As the number of introduced species keeps increasing unabatedly, identifying and prioritising current and potential Invasive Alien Species (IAS) has become essential to manage them. Horizon Scanning (HS), defined as an exploration of potential threats, is considered a fundamental component of IAS management. By combining scientific knowledge on taxa with expert opinion, we identified the most relevant aquatic IAS in the Iberian Peninsula, i.e., those with the greatest geographic extent (or probability of introduction), severe ecological, economic and human health impacts, greatest difficulty and acceptability of management. We highlighted the 126 most relevant IAS already present in Iberian inland waters (i.e., Concern list) and 89 with a high probability of being introduced in the near future (i.e., Alert list), of which 24 and 10 IAS, respectively, were considered as a management priority after receiving the highest scores in the expert assessment (i.e., top-ranked IAS). In both lists, aquatic IAS belonging to the four thematic groups (plants, freshwater invertebrates, estuarine invertebrates, and vertebrates) were identified as having been introduced through various pathways from different regions of the world and classified according to their main functional feeding groups. Also, the latest update of the list of IAS of Union concern pursuant to Regulation (EU) No 1143/2014 includes only 12 top-ranked IAS identified for the Iberian Peninsula, while the national lists incorporate the vast majority of them. This fact underlines the great importance of taxa prioritisation exercises at biogeographical scales as a step prior to risk analyses and their inclusion in national lists. This HS provides a robust assessment and a cost-effective strategy for decision-makers and stakeholders to prioritise the use of limited resources for IAS prevention and management. Although applied at a transnational level in a European biodiversity hotspot, this approach is designed for potential application at any geographical or administrative scale, including the continental one

Black list and Alert list of the Aquatic Invasive Alien Species in the Iberian Peninsula: an action of the LIFE INVASAQUA

Resumen del trabajo presentado en VI Congreso Nacional sobre Especies Exóticas Invasoras y I Congreso Ibérico sobre EEI (EEI 2022) celebrado en Navarra del 20 al 23 de abril de 2022.One of the objectives of LIFE INVASQUA project is to develop tools that will be more efficient the Early Warning and Rapid Response (EWRR) framework for Invasive Alien Species in the Iberian Peninsula. Horizon scanning for high-risk IAS is basic in implementing measures to reduce new invasions, developing Alert lists, and to focus effort in the species already established, for instance making a Black list. We developed a trans national horizon scanning exercise focused on inland waters of Spain and Portugal in order to provide a prioritized lists (Black list and Alert list) of aquatic IAS that may pose a threat to aquatic ecosystems and socio economic sectors in the future. We followed a step approach of existing information about IAS (Plants, Freshwater Invertebrates, Estuarine Invertebrates and Vertebrates; 127 established taxa in Black list; 90 non established taxa in Alert list) combining with an expert scoring of prioritized taxa. IAS established in the Iberian aquatic system consistently highlighted as the worst included vertebrates (e.g. Cyprinus carpio, Gambusia holbrooki, Silurus glanis), freshwater and estuarine invertebrates (e.g. Procambarus clarkii, Dreissena polymorpha, Pacifastacus leniusculus, Ficopomatus enigmaticus, Callinectes sapidus, Corbicula fluminea) and plants (e.g. Eichhornia crassipes, Azolla filiculoides, Ludwigia grandiflora). Amongst taxa not yet established (Alert list), expert pointed to Perna viridis, Hydroides dirampha, Dreissena bugensis, Procambarus fallax f. virginallis, Perccottus glenii with higher risk of invasion, ecological and socioeconomic impacts. Over 20.6% of the taxa in the preliminary black list received no votes (no prioritization) by experts, 17.8% in the innitial alert list. Our horizon scanning approach is inclusive of all-taxa, prioritizes both established and emerging biological threats across trans-national scales, and considers not only the ecological impact, but also potential direct economic consequences as well as the manageability of invasive species.This work received funds from the LIFE Programme (LIFE17 GIE/ES/000515)

Corrigendum to ‘a horizon scan exercise for aquatic invasive alien species in Iberian inland waters’

info:eu-repo/semantics/publishedVersio

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

LISTA NEGRA Y LISTA DE ALERTA DE ESPECIES EXÓTICAS INVASORAS ACUÁTICAS DE LA PENÍNSULA IBÉRICA - Ejercicio de exploración del horizonte transnacional centrado en las especies exóticas invasoras acuáticas de alto riesgo para las aguas interiores ibéricas.

Un objetivo importante de LIFE INVASAQUA es desarrollar herramientas que mejoren la gestión y sean más eficientes en el marco de Alerta Temprana y Respuesta Rápida (EWRR) para las Especies Exóticas Invasoras (EEI) en la Península Ibérica. La exploración del horizonte para las EEI de alto riesgo es básica para aplicar medidas que reduzcan las nuevas invasiones y para centrar los esfuerzos en las especies ya registradas. Desarrollamos un ejercicio transnacional de exploración del horizonte centrado en las aguas interiores de España y Portugal con el fin de proporcionar una lista negra de las EEI acuáticas actualmente establecidas y una lista de alerta de las EEI acuáticas potenciales que pueden suponer una amenaza para los ecosistemas acuáticos y los sectores socioeconómicos en el futuro. Para la exploración del horizonte seguimos un enfoque estructurado de 5 pasos que combinaba las pruebas existentes sobre las EEI con una puntuación de expertos de los taxones priorizados. En la lista negra final se priorizaron 126 EEI, que representan el 41,2% de los taxones exóticos registrados en las aguas continentales ibéricas. Las 24 primeras especies tenían un riesgo de impacto muy alto porque obtuvieron los valores máximos en el proceso de puntuación de la evaluación de riesgos. Además, la lista de alerta incluía 89 EEI con un riesgo significativo de invasión en la Península Ibérica en el futuro, estando 11 taxones en cabeza con un riesgo muy alto de invasión