Rotation curve bifurcations as indicators of close recent galaxy encounters

Rotation curves of interacting galaxies often show that velocities are either rising or falling in the direction of the companion galaxy. We seek to reproduce and analyse these features in the rotation curves of simulated equal-mass galaxies suffering a one-to-one encounter, as possible indicators of close encounters. Using simulations of major mergers in 3D, we study the time evolution of these asymmetries in a pair of galaxies, during the first passage. Our main results are: (a) the rotation curve asymmetries appear right at pericentre of the first passage, (b) the significant disturbed rotation velocities occur within a small time interval, of ~ 0.5 Gyr h^-1, and therefore the presence of bifurcation in the velocity curve could be used as an indicator of the pericentre occurrence. These results are in qualitative agreement with previous findings for minor mergers and fly-byes.Comment: 4 pages, 7 figure

Chemotherapeutic agent 5-fluorouracil increases survival of SOD1 mouse model of ALS

Amyotrophic lateral sclerosis (ALS) is a lethal motor neuron disease with no cure. Currently there are only two ALS drugs approved by the FDA, both with a limited therapeutic effect. In the search for drug candidates for ALS, we studied the effect of known stem cell mobilizing agents (treatment) and antimetabolite 5-fluorouracil (5-FU) (anti-treatment) in SOD1G93A model of ALS. Surprisingly, we found that anti-cancer drug 5-FU increases lifespan, delays the disease onset and improves motor performance in ALS mice. Although we were not able to demonstrate the mechanistic basis of the beneficial 5-FU action in ALS mice, our findings suggest that 5-FU or similar drugs are possible drug candidates for the treatment of motor neuron diseases through drug repurposing

Diodos emisores de luz para irradiación de plantas

Los recientes desarrollos conseguidos en el área de la iluminación con diodos emisores de luz (LEDs, cuando son inorgánicos, y OLEDs, cuando son orgánicos) resultan de gran interés en horticultura, al permitir manipular el espectro radiante que va a incidir sobre las plantas, con el objetivo de aumentar su producción o de generar determinados efectos fisiológicos, sobre todo en invernaderos. Puesto que los vegetales crecen mejor cuando son iluminados (irradiados) en las regiones roja y azul del espectro, resulta aconsejable sustituir los sistemas de iluminación fotosintética actuales, fundamentalmente mediante lámparas de descarga en gases (vapor de sodio a alta presión y, en menor medida, halogenuros metálicos), por LEDs comerciales que emiten separadamente en esas regiones o por OLEDs susceptibles de emisión conjunta. Además, estos dispositivos son más eficientes que las lámparas incandescentes (consumen mucha menor energía eléctrica y poseen una vida media de uso mucho más larga), no generan exceso de calor (y por tanto no dañan a plantas térmicamente sensibles), e incluso, en el caso de los LEDs rojos, repelen insectos, por lo que contribuyen a la disminución en el uso de agrotóxicos. En el presente artículo, se revisan las últimas contribuciones en Fitofotónica relacionadas con los diodos emisores de luz, se aporta la experiencia existente sobre la aplicación de LEDs a invernaderos y se divulga el estado de las investigaciones que algunos grupos de investigación estamos realizando sobre OLEDs emisores bien en el rojo o bien en las regiones del rojo y el azul

An N-body/SPH Study of Isolated Galaxy Mass Density Profiles

We investigate the evolution of mass density profiles in secular disk galaxy models, paying special attention to the development of a two-component profile from a single initial exponential disk free of cosmological evolution (i.e., no accretion or interactions). As the source of density profile variations, we examine the parameter space of the spin parameter, halo concentration, virial mass, disk mass and bulge mass, for a total of 162 simulations in the context of a plausible model of star formation and feedback (GADGET-2). The evolution of the galaxy mass density profile, including the development of a two-component profile with an inner and outer segment, is controlled by the ratio of the disk mass fraction, $m_{d}$, to the halo spin parameter, $\lambda$. The location of the break between the two components and speed at which it develops is directly proportional to $m_{d}/\lambda$; the amplitude of the transition between the inner and outer regions is however controlled by the ratio of halo concentration to virial velocity. The location of the divide between the inner and outer profile does not change with time. (Abridged)Comment: 27 pages, 31 figures. Accepted for publication at MNRAS. A high-resolution version of the paper with figures can be found here http://www.mpia-hd.mpg.de/~foyle/papers/MN-07-1491-MJ.R1.pd

Prevencion primaria y secundaria de la fractura de cadera por fragilidad ósea en la población del sector sanitario Teruel

Fundamentos: La osteoporosis puede y debe prevenirse, diagnosticarse y tratarse, preferentemente antes de que aparezca la fractura por fragilidad. El objetivo fue analizar las intervenciones de prevención primaria y secundaria llevadas a cabo en las personas que sufrieron fractura de cadera por fragilidad en 2014 en el sector sanitario de Teruel. Método: Estudio descriptivo transversal. Variables analizadas: sexo, edad, zona básica de salud, residencia, situación funcional basal, antecedente de osteoporosis, fractura de fémur o vertebral, pérdida de estatura, utilización de FRAX, tratamiento al alta, exitus y su causa. Se empleó t-Student y ANOVA para variables cuantitativas por categorías y regresión para relaciones lineales. Resultados: Se incluyó a 148 personas, de las cuales 123 eran mujeres, con una mediana de edad de 87 años, 27, 4% tenían dependencia grave o total para las actividades de la vida diaria, 33% estaban institucionalizados. El 10, 1% tenían antecedente de fractura de cadera y 10% de fractura vertebral. Constaba diagnóstico de osteoporosis en el 13’7%. En ningún caso se había utilizado la herramienta FRAX®. Habían seguido tratamiento previo con calcio el 12, 2%, con vitamina D el 11, 5% y con fármacos anti-osteoporóticos un 6, 8%. Tras la fractura siguió tratamiento para prevención secundaria el 52, 7%. A 31/12/2015 había fallecido un 25, 7%, con mediana de supervivencia de los fallecidos de 64, 5 días, siendo las causas de exitus más frecuentes enfermedad cardiovascular (42, 3%), infección (23, 1%) y neoplasias (11, 5%). Conclusiones: En nuestro sector sanitario es infrecuente la valoración de la osteoporosis y del riesgo de fractura en población de riesgo así como la indicación de medidas farmacológicas de prevención primaria. Aunque la indicación de terapia para la prevención secundaria es superior a la reflejada en la literatura, debemos tomar medidas adicionales para mejorar la prevención de fracturas por fragilidad. Background: Osteoporosis should be prevented, diagnosed and treated, preferably before the fragility fracture occurs. The objective was to analyze primary and secondary interventions carried out in individuals diagnosed with femur fragility fracture at Teruel in 2014. Methods: Descriptive retrospective study. Variables assessed were sex, age, main health district, place of residence, basal functional situation, diagnosis on osteoporosis, hip or vertebral fracture, loss of height, use of FRAX tool, treatment on discharge, survival and cause of exitus. Student''s t-test and ANOVA were used for quantitative variables by categories and regression for linear relationships. Results: 148 patients were included. 123 were women median age was 87 years, 123 ( 76, 4%) were women, 27, 4% of the patients were totally or severely dependent for activities of daily living and 33% of them were living in a nursing home. There was a previous history of hip fracture in 10, 1%, and one or more vertebral fractures in 10, 1%. FRAX r tool was not used in any case. 12, 2% of patients had been treated with calcium prior to fracture, 11, 5% with vitamin D, and 6, 8% of them with antiosteoporotic drugs. Only 52, 7% were treated for secondary prevention after discharge. At the end of follow-up, 25, 7% of hip fractured patients had died. Median survivorship of deceased patients was 64, 5 days. 42, 3% of exitus were caused by cardiovascular disease, 23, 1% by infection and 11, 5% by neoplasms. Conclusions: Primary pharmacologic prevention and assessment of osteoporosis or risk of fracture are unfrequent in our health district.. Although pharmacologic treatment is prescribed more frequently in Teruel than in other areas after a hip or vertebral fracture, additional measures should be taken in order to improve fragility fracture prevention

Immunosuppressive Minimization Strategies in Kidney Transplantation

The long-term graft survival in renal transplantation results is still controversial, the toxicity and adverse reactions of the immunosuppressive drugs are implicated, as well as cellular and humoral antigen-specific immune mechanisms; therefore, different strategies for adapting immunosuppression are used to reduce the complications associated with the use of these drugs. Calcineurin inhibitors (CNI) require an adequate dose-dependent concentration leading to the appearance of drug-related adverse reactions. The variability in the required dose of CNI leads to minimization strategies that do not result in a higher acute rejection (AR) incidence when compared to other immunosuppressive agents. Early steroid withdrawal is another strategy, although with an increase in AR, but without an impact on the function and survival of the renal graft. The reduction of mycophenolate mofetil to 1.5 g/day seems to be a therapeutic option, decreasing the infectious, hematological and gastrointestinal adverse reactions. Finally, alemtuzumab, bortezomib, belatacept and cellular therapies are in the search for the new treatments, whose premise is the induction of donor-specific nonresponse in the context of operational tolerance or mixed chimerism. The use of adapted and adequate immunosuppression has led to variable results and some are very encouraging; however, they must be validated with experimental studies

Field-level simulation-based inference with galaxy catalogs: the impact of systematic effects

It has been recently shown that a powerful way to constrain cosmological parameters from galaxy redshift surveys is to train graph neural networks to perform field-level likelihood-free inference without imposing cuts on scale. In particular, de Santi et al. (2023) developed models that could accurately infer the value of $\Omega_{\rm m}$ from catalogs that only contain the positions and radial velocities of galaxies that are robust to uncertainties in astrophysics and subgrid models. However, observations are affected by many effects, including 1) masking, 2) uncertainties in peculiar velocities and radial distances, and 3) different galaxy selections. Moreover, observations only allow us to measure redshift, intertwining galaxies' radial positions and velocities. In this paper we train and test our models on galaxy catalogs, created from thousands of state-of-the-art hydrodynamic simulations run with different codes from the CAMELS project, that incorporate these observational effects. We find that, although the presence of these effects degrades the precision and accuracy of the models, and increases the fraction of catalogs where the model breaks down, the fraction of galaxy catalogs where the model performs well is over 90 %, demonstrating the potential of these models to constrain cosmological parameters even when applied to real data.Comment: 29 pages, 11 figures. For the reference in the abstract (de Santi et al. 2023) see arXiv:2302.1410

In Vitro Studies Evaluating Leaching of Mercury from Mine Waste Calcine Using Simulated Human Body Fluids

In vitro bioaccessibility (IVBA) studies were carried out on samples of mercury (Hg) mine-waste calcine (roasted Hg ore) by leaching with simulated human body fluids. The objective was to estimate potential human exposure to Hg due to inhalation of airborne calcine particulates and hand-to-mouth ingestion of Hg-bearing calcines. Mine waste calcines collected from Hg mines at Almadén, Spain, and Terlingua, Texas, contain Hg sulfide, elemental Hg, and soluble Hg compounds, which constitute primary ore or compounds formed during Hg retorting. Elevated leachate Hg concentrations were found during calcine leaching using a simulated gastric fluid (as much as 6200 μg of Hg leached/g sample). Elevated Hg concentrations were also found in calcine leachates using a simulated lung fluid (as much as 9200 μg of Hg leached/g), serum-based fluid (as much as 1600 μg of Hg leached/g), and water of pH 5 (as much as 880 μg of Hg leached/g). The leaching capacity of Hg is controlled by calcine mineralogy; thus, calcines containing soluble Hg compounds contain higher leachate Hg concentrations. Results indicate that ingestion or inhalation of Hg mine-waste calcine may lead to increased Hg concentrations in the human body, especially through the ingestion pathway

Making Galaxies in a Cosmological Context: The Need for Early Stellar Feedback

We introduce the Making Galaxies in a Cosmological Context (MaGICC) program of smoothed particle hydrodynamics (SPH) simulations. We describe a parameter study of galaxy formation simulations of an L* galaxy that uses early stellar feedback combined with supernova feedback to match the stellar mass--halo mass relationship. While supernova feedback alone can reduce star formation enough to match the stellar mass--halo mass relationship, the galaxy forms too many stars before z=2 to match the evolution seen using abundance matching. Our early stellar feedback is purely thermal and thus operates like a UV ionization source as well as providing some additional pressure from the radiation of massive, young stars. The early feedback heats gas to >10^6 K before cooling to 10^4 K. The pressure from this hot gas creates a more extended disk and prevents more star formation prior to z=1 than supernovae feedback alone. The resulting disk galaxy has a flat rotation curve, an exponential surface brightness profile, and matches a wide range of disk scaling relationships. The disk forms from the inside-out with an increasing exponential scale length as the galaxy evolves. Overall, early stellar feedback helps to simulate galaxies that match observational results at low and high redshifts.Comment: 13 pages, 14 figures, accepted MNRAS, movies at http://www.mpia.de/~stinson/magic