Generation of three-qubit entangled states using coupled multi-quantum dots

We discuss a mechanism for generating a maximum entangled state (GHZ) in a coupled quantum dots system, based on analytical techniques. The reliable generation of such states is crucial for implementing solid-state based quantum information schemes. The signature originates from a remarkably weak field pulse or a far off-resonance effects which could be implemented using technology that is currently being developed. The results are illustrated with an application to a specific wide-gap semiconductor quantum dots system, like Zinc Selenide (ZnSe) based quantum dots.Comment: 8 pages, 2 figure

Energy resolution of terahertz single-photon-sensitive bolometric detectors

We report measurements of the energy resolution of ultra-sensitive superconducting bolometric detectors. The device is a superconducting titanium nanobridge with niobium contacts. A fast microwave pulse is used to simulate a single higher-frequency photon, where the absorbed energy of the pulse is equal to the photon energy. This technique allows precise calibration of the input coupling and avoids problems with unwanted background photons. Present devices have an intrinsic full-width at half-maximum energy resolution of approximately 23 terahertz, near the predicted value due to intrinsic thermal fluctuation noise.Comment: 11 pages (double-spaced), 5 figures; minor revision

Cardiovascular risk factors and memory decline in middle-aged and older adults: the English Longitudinal Study of Ageing

BACKGROUND: We investigated the association between trajectories of verbal episodic memory and burden of cardiovascular risk factors in middle-aged and older community-dwellers. METHODS: We analysed data from 4372 participants aged 50-64 and 3005 persons aged 65-79 years old from the English Longitudinal Study of Ageing who were repeatedly evaluated every 2 years and had six interviews of a 10-year follow-up. We measured the following baseline risk factors: diabetes, hypertension, smoking, physical inactivity and obesity to derive a cardiovascular risk factor score (CVRFs). Adjusted linear mixed effect regression models were estimated to determine the association between number of CVFRs and six repeated measurements of verbal memory scores, separately for middle-aged and older adults. RESULTS: CVRFs was not significantly associated with memory at baseline. CVFRs was significantly associated with memory decline in middle-aged (50-64y), but not in older (65-79y) participants. This association followed a dose-response pattern with increasing number of CVFRs being associated with greater cognitive decline. Comparisons between none versus some CVRFs yielded significant differences (p < 0.05). CONCLUSIONS: Our findings confirm that the effect of cumulative CVRFs on subsequent cognitive deterioration is age-dependent. CVRFs are associated with cognitive decline in people aged 50-64 years, but not in those aged ≥65 years. Although modest, the memory decline associated with accumulation of cardiovascular risk factors in midlife may increase the risk of late-life dementia

La bicicleta como transporte sostenible en México

De acuerdo a los datos publicados por el Banco Mundial (actualización 31 de octubre del 2012), México presentó una tendencia hacia la baja a pesar de esto, aún sigue siendo considerable sus emisiones de CO2 actualmente es de 3.98 ton per cápita. Esto contribuye al efecto invernadero y a su vez desequilibrios en nuestros ecosistemas. Siendo así uno de los eventos que aportan efectos al cambio climático. A partir de este planteamiento se busca llevar a cabo propuestas viables y que motiven a la creación de un sistema que sea respetuoso con el medio ambiente con un desarrollo económico local y eficientizar la infraestructura existente además de mejorar la imagen urbana así como promover la salud a través del uso de la bicicleta, así mismo tener una ciudad más competitiva con reducciones de emisiones de carbono que abone a la reducción del cambio climático. Para contribuir en su mitigación, se impulsa la realización del Plan de Movilidad Ciclista de Ensenada, con el fin de mejorar la calidad de vida de la población y mejorar las condiciones actuales de los problemas medioambientales al participar en la reducción de CO2 y promover el uso de la bicicleta como medio de transporte no motorizado. El proyecto, en su primera fase, consiste en retirar 166 aparcamientos dispuestos a lo largo del Boulevard Costero de la zona turística en aparcamientos públicos, y así usar este espacio para desarrollar una ruta de la ciclovía. Comprobamos que uno de los medios de transporte más vendidos en México (no así en el 2012) es el Nissan Tsuru 2008, por ser un auto económico y de bajo mantenimiento. Analizamos la emisión del CO2, considerándolo como un vehículo de rango medio en la eficiencia de emisión de gases contaminantes, y si consideramos que el 34.14% (como valor representativo) de los autos que ya no estarían estacionados en esa vialidad se sustituyen por uso de bicicleta, obtenemos que la reducción de emisiones de CO2 durante un año al implementar la primera fase del Plan de Movilidad Ciclista, es de 71,76 tonelada

Association between traumatic events and post-traumatic stress disorder: results from the ESEMeD-Spain study

Background: The relative importance of traumatic events (TEs) in accounting for the social burden of post-traumatic stress disorder (PTSD) could vary according to cross-cultural factors. In that sense, no such studies have yet been conducted in the Spanish general population. The present study aims to determine the epidemiology of trauma and PTSD in a Spanish community sample using the randomly selected TEs method. Methods: The European Study of the Epidemiology of Mental Disorders (ESEMeD)-Spain is a cross-sectional household survey of a representative sample of adult population. Lifetime prevalence of self-reported TEs and lifetime and 12-month prevalence of PTSD were evaluated using the World Health Organization (WHO) Composite International Diagnostic Interview. Reports of PTSD associated with randomly selected TEs were weighted by the individual-level probabilities of TE selection to generate estimates of population-level PTSD risk associated with each TE. Results: Road accident was the most commonly self-reported TE (14.1%). Sexual assault had the highest conditional risk of PTSD (16.5%). The TEs that contributed most to societal PTSD burden were unexpected death of a loved one (36.4% of all cases) and sexual assault (17.2%). Being female and having a low educational level were associated with low risk of overall TE exposure and being previously married was related to higher risk. Being female was related to high risk of PTSD after experiencing a TE. Conclusions: Having an accident is commonly reported among Spanish adults, but two TE are responsible for the highest burden associated with PTSD: the unexpected death of someone close and sexual assault. These results can help designing public health interventions to reduce the societal PTSD burden

Optical signatures of quantum phase transitions in a light-matter system

Information about quantum phase transitions in conventional condensed matter systems, must be sought by probing the matter system itself. By contrast, we show that mixed matter-light systems offer a distinct advantage in that the photon field carries clear signatures of the associated quantum critical phenomena. Having derived an accurate, size-consistent Hamiltonian for the photonic field in the well-known Dicke model, we predict striking behavior of the optical squeezing and photon statistics near the phase transition. The corresponding dynamics resemble those of a degenerate parametric amplifier. Our findings boost the motivation for exploring exotic quantum phase transition phenomena in atom-cavity, nanostructure-cavity, and nanostructure-photonic-band-gap systems.Comment: 4 pages, 4 figure

Prevalence of depression during the COVID-19 outbreak: A meta-analysis of community-based studies

Introduction: COVID-19 pandemic, declared on March 11, 2020, constitute an extraordinary health, social and economic global challenge. The impact on people''s mental health is expected to be high. This paper sought to systematically review community-based studies on depression conducted during the COVID-19 and estimate the pooled prevalence of depression. Method: We searched for cross-sectional, community-based studies listed on PubMed or Web of Science from January 1, 2020 to May 8, 2020 that reported prevalence of depression. A random effect model was used to estimate the pooled proportion of depression. Results: A total of 12 studies were included in the meta-analysis, with prevalence rates of depression ranging from 7.45% to 48.30%. The pooled prevalence of depression was 25% (95% CI: 18% - 33%), with significant heterogeneity between studies (I2 = 99.60%, p &lt; .001). Conclusions: Compared with a global estimated prevalence of depression of 3.44% in 2017, our pooled prevalence of 25% appears to be 7 times higher, thus suggesting an important impact of the COVID-19 outbreak on people's mental health. Addressing mental health during and after this global health crisis should be placed into the international and national public health agenda to improve citizens’ wellbeing

From Cu(i) and Cu(i)–Cu(ii) mixed-valence clusters to 2D Cu(ii) and Cu(i) coordination polymers supported by a flexible bis-tetrazole organosulfur ligand

Three coordination compounds from the reaction of copper(II) bromide with the flexible bis-tetrazole organosulfur ligand, 1,2-bis(1-methyl-1H-tetrazole-5-ylthio)ethane (bmtte) have been isolated and characterised. The identification of polymeric 2Cu2Br4 (bmtte) (1), trinuclear [Cu3Br4(bmtte)2] (2) and tetra-nuclear [Cu2Br2(bmtte)]2 (3) compounds shows that the reaction conditions have a significant influence on the structure of the complexes formed. Moreover, two polymorphs of the 2D Cu(II )-coordination polymer 1 have been isolated and these crystallise in the monoclinic C2/m (1m) and the triclinic P1¯ (1t) space groups. The thermal stabilities and behaviour in aqueous media of compounds 1–3 were investigated along with the reactivity of compound 2 with CuBr2 and KI. The solid-state reaction between mixed-valence compound 2 with KI or the direct reaction of CuI and bmtte under microwave irradiation allowed the preparation of the polymeric 2 1Cu4 I4 (bmtte)2 (4). The redox behaviour of complexes 2 and 3 was analysed by cyclic voltammetry.Agencia Estatal de Investigación | Ref. PID2019-110218RB-I00Agencia Estatal de Investigación | Ref. PID2020-115004RB-I00Fundación CajaCanarias | Ref. 2021ECO11Xunta de GaliciaUniversidad de La Lagun

Changes in depression and suicidal ideation under severe lockdown restrictions during the first wave of the COVID-19 pandemic in Spain: a longitudinal study in the general population - RETRACTION

El texto del artículo original se encuentra disponible en http://hdl.handle.net/10486/70204

Impact of multimorbidity on disability and quality of life in the Spanish older population

Background Population aging is closely related to high prevalence of chronic conditions in developed countries. In this context, health care policies aim to increase life span cost-effectively while maintaining quality of life and functional ability. There is still, however, a need for further understanding of how chronic conditions affect these health aspects. The aim of this paper is to assess the individual and combined impact of chronic physical and mental conditions on quality of life and disability in Spain, and secondly to show gender trends. Methods Cross-sectional data were collected from the COURAGE study. A total of 3,625 participants over 50 years old from Spain were included. Crude and adjusted multiple linear regressions were conducted to detect associations between individual chronic conditions and disability, and between chronic conditions and quality of life. Separate models were used to assess the influence of the number of diseases on the same variables. Additional analogous regressions were performed for males and females. Results All chronic conditions except hypertension were statistically associated with poor results in quality of life and disability. Depression, anxiety and stroke were found to have the greatest impact on outcomes. The number of chronic conditions was associated with substantially lower quality of life [ß for 4+ diseases: -18.10 (-20.95,-15.25)] and greater disability [ß for 4+ diseases: 27.64 (24.99,30.29]. In general, women suffered from higher rates of multimorbidity and poorer results in quality of life and disability. Conclusions Chronic conditions impact greatly on quality of life and disability in the older Spanish population, especially when co-occurring diseases are added. Multimorbidity considerations should be a priority in the development of future health policies focused on quality of life and disability. Further studies would benefit from an expanded selection of diseases. Policies should also deal with gender idiosyncrasy in certain cases