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Descríbese a utilidade do cambio de hora

A short take on the pros and cons associated with daylight saving time

The assessment of the acute impact of daylight saving time (DST) transitions is a question of great interest for an understanding of the benefits and inconveniences of a practice that is now under public scrutiny in Europe and America. Here, we report a thorough analysis of a record of 13 well-known research studies that reported increased risks associated with DST transitions in health issues – acute myocardial infarction, ischemic strokes and trauma admissions – and in societal issues – accidents, traffic accidents and fatal motor vehicle accidents. We found that a five percent increase of the risks suffices to understand the reported increased risks associated with the spring transition. Reported values above this threshold are impacted by the sample size of the study. In the case of the autumn transition, no increase in the risks is found.

Objective To describe a method to calculate the total intra-articular volume (inter-osseous space) of the temporomandibular joint (TMJ) determined by cone-beam computed tomography (CBCT). This could be used as a marker of tissue proliferation and different degrees of soft tissue hyperplasia in juvenile idiopathic arthritis (JIA) patients. Materials and Methods Axial single-slice CBCT images of cross-sections of the TMJs of 11 JIA patients and 11 controls were employed. From the top of the glenoid fossa, in the caudal direction, an average of 26 slices were defined in each joint (N = 44). The interosseous space was manually delimited from each slice by using dedicated software that includes a graphic interface. TMJ volumes were calculated by adding the areas measured in each slice. Two volumes were defined: Ve−i and Vi, where Ve−i is the inter-osseous space, volume defined by the borders of the fossa and Vi is the internal volume defined by the condyle. An intra-articular volume filling index (IF) was defined as Ve−i/Vi, which represents the filling of the space. Results The measured space of the intra-articular volume, corresponding to the intra-articular soft tissue and synovial fluid, was more than twice as large in the JIA group as in the control group. Conclusion The presented method, based on CBCT, is feasible for assessing inter-osseus joint volume of the TMJ and delimits a threshold of intra-articular changes related to intra-articular soft tissue proliferation, based on differences in volumes. Intra-articular soft tissue is found to be enlarged in JIA patients

A plethora of temperature-induced phase transitions have been observed in (CH3NH3)[M(HCOO)3] compounds, where M is Co(II) or Ni(II). Among them, the nickel compound exhibits a combination of magnetic and nuclear incommensurability below Néel temperature. Despite the fact that the zero-field behavior has been previously addressed, here we study in depth the macroscopic magnetic behavior of this compound to unveil the origin of the atypical magnetic response found in it and in its parent family of formate perovskites. In particular, they show a puzzling magnetization reversal in the curves measured starting from low temperatures, after cooling under zero field. The first atypical phenomenon is the impossibility of reaching zero magnetization, even by nullifying the applied external field and even compensating it for the influence of the Earth’s magnetic field. Relatively large magnetic fields are needed to switch the magnetization from negative to positive values or vice versa, which is compatible with a soft ferromagnetic system. The atypical path found in its first magnetization curve and hysteresis loop at low temperatures is the most noticeable feature. The magnetization curve switches from more than 1200 Oe from the first magnetization loop to the subsequent magnetization loops. A feature that cannot be explained using a model based on unbalanced pair of domains. As a result, we decipher this behavior in light of the incommensurate structure of this material. We propose, in particular, that the applied magnetic field induces a magnetic phase transition from a magnetically incommensurate structure to a magnetically modulated collinear structure

The evolution of some epidemics, such as influenza, demonstrates common patterns both in different regions and from year to year. On the contrary, epidemics such as the novel COVID-19 show quite heterogeneous dynamics and are extremely susceptible to the measures taken to mitigate their spread. In this paper, we propose empirical dynamic modeling to predict the evolution of influenza in Spain’s regions. It is a non-parametric method that looks into the past for coincidences with the present to make the forecasts. Here, we extend the method to predict the evolution of other epidemics at any other starting territory and we also test this procedure with Spanish COVID-19 data. We finally build influenza and COVID-19 networks to check possible coincidences in the geographical distribution of both diseases. With this, we grasp the uniqueness of the geographical dynamics of COVID-19

By March 14th 2022, Spain is suffering the sixth wave of the COVID-19 pandemic. All the previous waves have been intimately related to the degree of imposed mobility restrictions and its consequent release. Certain factors explain the incidence of the virus across regions revealing the weak locations that probably require some medical reinforcements. The most relevant ones relate with mobility restrictions by age and administrative competence, i.e., spatial constrains. In this work, we aim to find a mathematical descriptor that could identify the critical communities that are more likely to suffer pandemic outbreaks and, at the same time, to estimate the impact of different mobility restrictions. We analyze the incidence of the virus in combination with mobility flows during the so-called second wave (roughly from August 1st to November 30th, 2020) using a SEIR compartmental model. After that, we derive a mathematical descriptor based on linear stability theory that quantifies the potential impact of becoming a hotspot. Once the model is validated, we consider different confinement scenarios and containment protocols aimed to control the virus spreading. The main findings from our simulations suggest that the confinement of the economically non-active individuals may result in a significant reduction of risk, whose effects are equivalent to the confinement of the total population. This study is conducted across the totality of municipalities in Spain

French and Dutch are two languages of different origins (Germanic vs. Romance) that coexist within the nation-state of Belgium. While they are mostly segregated throughout the Belgian territory, in Brussels they reach an actual cohabitation with a relevant bilingual population. The dominant language in Brussels shifted from Dutch to French during the late XIX century in a process known as the Francization of Brussels. The fractions of speakers of each language and of bilinguals over that time were recorded periodically until political tensions ended the censuses in the country. This relevant linguistic shift has been the object of sociopolitical studies, but the available empirical data have never before been analyzed using a theoretical mathematical model that would allow us to quantify causal factors behind the observed dynamics. Here we carry out such study for the first time, measuring effective values of perceived interlinguistic similarity and language prestige, among others. This modeling and quantification allows us to speculate about possible trajectories of fractions of speakers over time—specifically, whether Dutch and French tend to be languages that can coexist in the long term. We find that there is an overall tendency of both tongues to grow segregated over time, suggesting, in physics terms, that Dutch and French are not miscible. The scenarios that would allow for language coexistence would often see a starkly dominating language. Notwithstanding, we also discuss the costs of attempting to sustain the cohabitation despite a natural tendency to the contrary

The COVID-19 pandemic has forced policy makers to decree urgent confinements to stop a rapid and massive contagion. However, after that stage, societies are being forced to find an equilibrium between the need to reduce contagion rates and the need to reopen their economies. The experience hitherto lived has provided data on the evolution of the pandemic, in particular the population dynamics as a result of the public health measures enacted. This allows the formulation of forecasting mathematical models to anticipate the consequences of political decisions. Here we propose a model to do so and apply it to the case of Portugal. With a mathematical deterministic model, described by a system of ordinary differential equations, we fit the real evolution of COVID-19 in this country. After identification of the population readiness to follow social restrictions, by analyzing the social media, we incorporate this effect in a version of the model that allow us to check different scenarios. This is realized by considering a Monte Carlo discrete version of the previous model coupled via a complex network. Then, we apply optimal control theory to maximize the number of people returning to “normal life” and minimizing the number of active infected individuals with minimal economical costs while warranting a low level of hospitalizations. This work allows testing various scenarios of pandemic management (closure of sectors of the economy, partial/total compliance with protection measures by citizens, number of beds in intensive care units, etc.), ensuring the responsiveness of the health system, thus being a public health decision support tool

Significance: The options that can help subjects with congenital color vision defect, to a better professional and leisure adaptation, are very limited. Different haploscopic lenses can be considered, and their effects need to be investigated in patients with different defect. Purpose: The purpose of this study was to present and discuss the effect of a pair of asymmetric longpass filters fitted for deuteranopia, with the result of a 60% improvement on distinguishing red-green plates when compared with baseline. Case Report: We report a case of a 51-year-old male with congenital deuteranopia fitted with haploscopic Chromagen filters. During the 2-month follow-up, we observed a decrease in left eye logMAR visual acuity and contrast sensitivity with an increased ability to discriminate the plates of different color vision tests (Ishihara, Farnsworth and Hardy-Rand-Rittler). The visual outcomes are discussed considering the spectral sensitivity curves of each filter, measured with a spectrophotometric device. Conclusions: This report describes an improvement in the ability to resolve color vision plates after using asymmetric haploscopic filters showing a left eye decrease in logMAR visual acuity and contrast sensitivity function. Subjects with a history of color vision deficiency might benefit from using haploscopic filters that selectively minimize the transmittance within a specific bandwidth in order to improve the color discrimination in deutan colour vision deficiency. The simultaneous analysis of the color vision outcomes and transmittance spectrum of the haploscopic filters might contribute to a better understanding of the mechanisms behind the claimed efficacy of these devices.

En este artículo se analizan las dificultades de aprendizaje de la Teoría de la Relatividad Restringida deEinstein. La información se ha obtenido y seleccionado de las bases de datos Web of Science, Scopus,Educational Resources Information Center y Google Scholar, teniendo en cuenta los índices de valoraciónJournal Citation Reports (JCR), Scimago Journal Rank (SJR) e Índice Compuesto de Difusión Secundaria (ICDS).Para el análisis y las conclusiones se establecieron las dificultades de aprendizaje del alumnado relacionadas con laRelatividad Restringida de Einstein, respecto a los siguientes conceptos: Espacio y tiempo. Causalidad ysimultaneidad. Sistemas de referencia. Energía. Masa. Luz. El presente estudio ha constituido el fundamento del diseño de una propuesta de enseñanza basada en laformulación geométrica de Minkowski, dirigida a estudiantes de bachillerato, In this article we analyze the learning difficulties of Einstein's Theory of Restricted Relativity. The information has been obtained and selected from the Web of Science, Scopus, Educational Resources Information Center and Google Scholar databases, taking into account the Journal Citation Reports (JCR),Scimago Journal Rank (SJR) and Composite Index of Secondary Dissemination (ICDS).For the analysis and the conclusions the learning difficulties of the students related to the Restricted Relativity of Einstein were established, with respect to the following concepts: Space and time. Causality and simultaneity. Reference frames. Energy. Mass. Light. This study has been the basis for the design of a teaching proposal based on the geometric formulation of Minkowski, aimed at high school students

Revísase a historia da física dos buratos negros, dende a primeira vez na que apareceu o concepto ata a obtención da primeira fotografía dun deles, o que supón un punto de inflexión na historia da astrofísica

We study the stability of Catalan and Spanish coexistence in Catalonia, a key political and economic European region. Recent, abundant empirical data of language use is analyzed within an analytic model of population dynamics. This model contemplates the possibilities of both long-term language coexistence and decline. The data needs to be interpreted under different circumstances. The most likely scenario, we find, is a sustained coexistence. Extreme cases still lead to the decline of one of the tongues–we delimit when this can happen. Asymptotic behavior is often an unreliable predictor in complex social systems; we make an attempt at forecasting fractions of speakers towards 2030. These also suggest sustained coexistence, but some counterintuitive dynamics are unveiled. Model parameters estimated from the data convey relevant information about the prestige and interlinguistic similarity of both tongues. We quantify these parameters rigorously for these languages for the first time. Remarkably, Spanish is found to have a larger prestige in areas which historically had larger Catalan monolingual communities. With limited, spatially-segregated data we examine more fine grained dynamics, thus better addressing the likely outcomes. Differences in model parameters across regions reveal how the two languages are perceived in more urban or rural environments

With the recent development of nanotechnology, magnetic nanoparticles (mNPs) have received increasing attention as potential heterogeneous Fenton catalysts in wastewater treatment applications, as an alternative to the conventional Fenton process using dissolved iron salts. Due to their superparamagnetic properties, Fe3O4 mNPs can be easily recovered and reused by applying a magnetic field. However, Fe3O4 mNPs have a marked tendency to form aggregates in water, leading to a decrease in their catalytic yield. To overcome these limitations, this work explores the catalytic activity of Fe3O4 coated with poly(acrylic acid) (Fe3O4@PAA) as stabilized Fenton heterogeneous nanocatalyst, in the degradation of C.I. Reactive Blue 19 (RB19). To maximize the catalytic potential of Fe3O4@PAA, an experimental design based on the Response Surface Methodology (RSM) has been developed to optimize the conditions of the Fenton process in terms of Fe3O4@PAA concentration (100–300 mg L−1) and H2O2 dose (100–400 mg L−1). Based on the results obtained, a novel sequential batch reactor (SBR) coupled to an external magnetic separation system has been developed, guaranteeing the complete retention of the mNPs in the system. This system allows the reuse of Fe3O4@PAA for at least 10 consecutive cycles, with a successful decolorization of RB19 after 4 h of treatment

Sociolinguistic phenomena often involve interactions across different scales and result in social and linguistic changes that can be tracked over time. Here, we focus on the dynamics of language shift in Galicia, a bilingual community in northwest Spain. Using historical data on Galician and Spanish speakers, we show that the rate at which shift dynamics unfold correlates inversely with the internal complexity of a region (approximated by the proportion of urban area). Less complex areas converge faster to steady states, while more complex ones sustain transitory dynamics longer. We further explore the contextual relevance of each region within the network of regions that constitute Galicia. The network is observed to sustain or reverse the dynamic rates. This model can introduce a competition between the internal complexity of a region and its contextual relevance in the network. Harnessing these sociodynamic features may prove useful in policy making to limit conflicts

La figura de Domingo de Soto es relevante en la Iglesia del siglo XVI, pero lo que no es tan conocido son sus contribuciones pioneras a la física. Sus acertadas reflexiones sobre la caída libre de los cuerpos y el concepto de masa aportaron un cambio cualitativo, que pudo haber influido más tarde en el pensamiento de grandes figuras de la historia de la ciencia, The figure of Domingo de Soto is relevant in the Church of the XVI century, but what is not so well known are his pioneering contributions to physics. His accurate reflections on the free fall of bodies and the concept of mass contributed to a qualitative change, which could have later influenced the thinking of great figures in the history of science

Debido a la inclinación cambiante del eje de rotación terrestre respecto al sol, se puede contemplar durante dos meses al año el último atardecer de la Europa continental en la zona más occidental de España (Costa da Morte), pese a no ser esta la más occidental del continente. El trabajo en el que se describió el calendario de esos atardeceres ha tenido incidencia en las estrategias turísticas de los ayuntamientos de la zona, que han comenzado a explotar este recurso natural

Recent contributions address the problem of language coexistence as that of two species competing to aggregate speakers, thus focusing on the dynamics of linguistic traits across populations. They draw inspiration from physics and biology and share some underlying ideas - e. g. the search for minimal schemes to explain complex situations or the notion that languages are extant entities in a societal context and, accordingly, that objective, mathematical laws emerge driving the aforementioned dynamics. Di erent proposals pay attention to distinct aspects of such systems: Some of them emphasize the distribution of the population in geographical space, others research exhaustively the role of bilinguals in idealized situations (e. g. isolated populations), and yet others rely extremely on equations taken unchanged from physics or biology and whose parameters bear actual geometrical meaning. Despite the sources of these models - so unrelated to linguistics - sound results begin to surface that establish conditions and make testable predictions regarding language survival within populations of speakers, with a decisive role reserved to bilingualism. Here we review the most recent works and their interesting outcomes stressing their physical theoretical basis, and discuss the relevance and meaning of the abstract mathematical ndings for real-life situations

A teoría da relatividade restrinxida e xeral supón un dos cumios da capacidade intelectual do ser humano. Reformulou os conceptos de espazo e tempo, a comprensión da orixe e evolución do Universo, e propiciou a entrada na era nuclear. Para os historiadores de dentro duns séculos esta fazaña do xenial físico Albert Einstein será un dos fitos do século XX. Hai multitude de libros divulgativos sobre ela, pero este ten o decisivo valor de ser escrito polo mesmo Einstein en 1916, ano seguinte ao de presentación da relatividade xeral. O esforzo do autor por chegar a un público amplo queda patente na linguaxe e didáctica empregadas, pensadas para achegarse á persoa que pasa as páxinas e evitar complexidades matemáticas. Estrutúrase en dúas metades, unha para a relatividade restrinxida e outra para a xeral. Grazas ao Consello da Cultura Galega, unha obra desta magnitude ve agora a luz en galego, incorporando dúas pezas introdutorias e a versión facsimilar. Tradúcese a primeira das edicións, que foi publicada en 1917, antes da espectacular observación en 1919 da curvatura da luz por efectos gravitatorios, o que supuxo a primeira confirmación das predicións da relatividade xeral e catapultou a Einstein a unha popularidade global

El debate público suscitado en los últimos tiempos sobre la conveniencia o no del cambio del huso horario en Galicia, en particular, y en España, en general, y su resolución en uno u otro sentido afecta a todos los niveles de la población, así como a sus hábitos y costumbres. No es, por lo tanto, un tema menor y sus consecuencias tienen un componente cultural indudable. Es por ello que el Consello consideró pertinente realizar a partir de su Sección de Ciencia, Natureza e Sociedade, en octubre del pasado año 2016, un debate, con defensores de una u otra postura, en relación con los cambios en el huso horario. Conscientes del interés de este encuentro, tomó la decisión de publicar (en formato digital, en gallego y castellano) el presente libro basado en las ponencias presentadas en el mismo, deseando que su lectura y difusión contribuyan a favorecer un diálogo sereno y asentado, sobre todo, en el mejor conocimiento del que se dispone en la actualidad. Solo así se podrá caminar hacia fórmulas de convivencia que sean constructivas y de futuro

O debate público suscitado nos últimos tempos sobre a conveniencia ou non do cambio do fuso horario en Galicia, en particular, e en España, en xeral, e a súa resolución nun ou noutro sentido afecta a todos os niveis da poboación, así como aos hábitos e costumes. É por isto que o Consello da Cultura Galega considerou pertinente realizar a partir da súa Sección de Ciencia, Natureza e Sociedade, en outubro do pasado ano 2016, un debate, con defensores dunha ou outra postura, en relación cos cambios no fuso horario. Conscientes do interese deste encontro, tomouse a decisión de publicar (en formato dixital, en galego e castelán) o presente libro baseado nos relatorios presentados no mesmo, desexando que a súa lectura e difusión contribúan a favorecer un diálogo sereno e asentado, sobre todo, no mellor coñecemento do que se dispón na actualidade

Juvenile idiopathic arthritis is the most common inflammatory rheumatic disease of childhood and the involvement of the temporomandibular joint has been reported in different studies. A number of scanning modalities can be used, and each modality uses a different physical effect to generate cross-sectional images through the human body. The cross-sectional images are arranged in order so that the computer can construct a three-dimensional data set of the patient.The three-dimensional visualizing method may, besides providing diagnostic advantages, be a valuable tool for qualitative and quantitative documentation of the efficiency of different treatment in patients with TMJ arthritis.