Artículos

Permanent URI for this collectionhttps://docta.ucm.es/handle/20.500.14352/15

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No evidence for Keplerian taper of far-out galactic rotation in the SPARC galaxy database
(New Astronomy, 2026) Bariego Quintana, Adriana; Llanes Estrada, Felipe José
We present a statistical analysis of the 175 SPARC galactic rotation curves to test the hypothesis of whether the Keplerian velocity tapering at large radii (𝑉 (𝑟) ∝ 1∕√𝑟) germane to a convergent mass distribution in typical spherical halo models agrees with observational data. The null hypothesis is Rubin’s flat-rotation curve, 𝑉 (𝑟) = constant -such as can be obtained from a spherical, isothermal-like density profile, or alternatively with a very prolate halo-. To decide whether we adopt the null (Rubin behaviour) or alternative (Keplerian behaviour) hypothesis, we evaluate the derivative in each galaxy of 𝑉 (𝑟) with its last data points. The test is model independent inasmuch we are testing for the slope of the dark matter rotation curve, whether it is or not compatible with zero. We conclude that the data is presently compatible with the null hypothesis — no taper off, no decline of 𝑉 (𝑟) is seen. Separately, beyond SPARC, our own Milky Way galaxy, for which recent data sets have been reported, does show clear 𝑉 (𝑟) fall-off at the level of 20%.
'Capricho' Avoiding Fear in Encounters with Spirits in the Andes
(Etnografia Polska, 2024) Muñoz Morán, Óscar
This article analyses encounters of Quechua peasants in the Potosí region of Bolivia with sajra espíritus (evil spirits). In order to ensure that these spirits do not cause them too much harm, they must not be afraid and this fearless state is achieved by means of what they call capricho. This word refers to a set of courageous actions during the encounter, which mainly allow the waylaid person to recognise the spirit and therefore to know how to deal with it. But this whole process must be shared and verbalised. Thus, capricho extends beyond the event and is also present in the transmission of the experience.
Cuerpos de agua. Perspectivas indígenas sobre territorios acuáticos y sus entidades
(Revista Kawsaypacha: Sociedad y Medio Ambiente, 2026) Muñoz Morán, Óscar
RESUMEN: Las crisis climáticas y medioambientales del planeta están estrechamente vinculadas con cambios en los estados del agua (i.e., su escasez, exceso, contaminación, desperdicio, etc.). El objetivo del dossier es ampliar el campo de visión para abordar las crisis del «agua», focalizando en las posibilidades de su diversidad ontológica. En muchas mitologías amerindias, por ejemplo, la emergencia de cursos de agua compone los paisajes originarios, al igual que las trombas de agua o los diluvios marcan momentos de rupturas y crisis. Además, en estas cosmologías, el agua es un conector en las relaciones entre humanos y entre otros seres y entidades que habitan el mundo. Así, las contrariedades vinculadas con el agua son abordadas no solo como el problema con un recurso preciado que precisa de soluciones técnicas efectivas, sino, sobre todo, como una cuestión relacional. Seres y dueños de los cuerpos de agua (ríos, lagunas, manantiales, etc.), a menudo conceptualizados como personas con capacidad de pensamiento, acción y comunicación, pueden ausentarse temporalmente, enfermarse, aletargarse o molestarse como respuesta a las acciones de los seres humanos o, incluso, de otros seres. Este dossier propone reunir investigaciones etnográficas para debatir: ¿Cuál es el estatuto ontológico del agua considerada, al mismo tiempo, como recurso y como agencia? ¿En qué circunstancias o redes de relaciones se desvelan las potencialidades agentivas del agua y de las entidades que habitan los cuerpos de agua? ¿Cuáles son las formas que toma su agentividad? ¿Cómo funcionan las redes de relaciones que implican al agua? ¿A qué agente involucran y cómo interaccionan para producir, definir e innovar soluciones a las «crisis del agua»? Finalmente, se discutirá cómo, a partir de los conocimientos indígenas vinculados con el agua y las entidades no-humanas vinculadas a los diferentes ecosistemas acuáticos, es posible imaginar no solamente nuevas metodologías de investigación, sino también una diferente cultura científica y nuevas formas de justicia epistémica, que permiten innovar y pensar de forma inédita las nociones y prácticas de conservación, restauración ecológica, gestión de los recursos y estudios ambientales.
P2X7 receptor or TNAP genetic blockade prevents the reduction of neuronal CTCF detected in tauopathy
(Neuropharmacology, 2026) Aivar, Paloma; Sebastián Serrano, Álvaro; Vincelle-Nieto, África; Collado-Cantero, Ana C; Ouro-Corredera, Daniel; Soria Tobar, Lucía; Reyes Palomares, Armando Adolfo; Díaz Hernández, Miguel
Intraneuronal aggregates assembled by hyperphosphorylated Tau protein are a common feature of a neurodegenerative disease family, namely Tauopathies. Recent studies have revealed that the ionotropic purinergic receptor P2X7 (P2X7R) and the ectoenzyme tissue-nonspecific alkaline phosphatase (TNAP) are upregulated in patients with tauopathies. Despite the molecular mechanisms underlying their upregulation remaining unknown, several studies suggest that genetic or pharmacological blocking of both proteins may represent a promising therapeutic strategy. Here, we performed transcriptomic analyses of bulk RNA-seq data from human cortical samples and revealed altered activity of multiple transcription factors (TFs) in tauopathy patients. Among the most affected TFs, we focused on the chromatin organizer CCCTC-binding factor (CTCF), as it was the only one that bound both the P2X7R and TNAP promoters. Gene expression deconvolution analyses revealed altered CTCF expression in both neuronal and glial populations from tauopathy patients. Consistently, immunofluorescence analyses in P301S mice, a tauopathy mouse model, showed a significant reduction in neuronal CTCF expression and a substantial increase in the number of glial cells with CTCF labelling. In vitro studies using neuroblastoma N2a cells confirmed that CTCF overexpression caused a transcriptional upregulation of both P2X7R and TNAP. Moreover, the fact that P2X7R activation or TNAP blockade decreases CTCF nuclear translocation suggests a bidirectional regulation. In line with these findings, we found that selective genetic P2X7R depletion or, unexpectedly, TNAP heterozygosity prevented the reduction of neuronal CTCF expression in P301S mice. Altogether, these data suggest that the newly identified TNAP/P2X7R/CTCF signaling axis is a crucial molecular mechanism underlying tauopathies.
Todos los Santos: tradición y ayllu andino
(Chungará, 2017) Muñoz Morán, Óscar
RESUMEN: Los rituales dedicados a la muerte han ocupado siempre un lugar privilegiado dentro de la etnografía andina. Habitualmente analizados desde la funcionalidad o semiótica de los mismos, no ha sido habitual, como sí ha sucedido con otras prácticas regionales, encuadrarlas dentro de estructuras mayores. En este artículo me propongo analizar el momento actual de un ayllu quechua de Potosí, Bolivia, desde la lectura etnográfica (presente y pasada) de la fiesta de Todos los Santos. Esta festividad se presenta como el fiel reflejo del proceso de transformación intensa que está viviendo una estructura tan compleja como es el ayllu.
El diablo y la enfermedad: precisiones en cuanto al concepto de susto/espanto entre los indígenas de Michoacán, Mexico
(Nuevo Mundos Mundos Nuevos, 2011) Muñoz Morán, Óscar
RESUMEN: El susto entre los purépechas es, en la actualidad, una enfermedad que, al menos en algunas de sus formas, aparece como sanción a un mal comportamiento social. Además, el dador último de dicha enfermedad no son entidades de origen prehispánico como comúnmente se ha aducido, sino el diablo en sus múltiples presencias. La enfermedad funciona, por tanto, como aviso al individuo que está rompiendo el equilibrio comunitario y, el diablo, como la representación simbólica de dicho desorden. La forma de hacer frente a estas fuerzas se construye mediante el costumbre local y el catolicismo moderno.
Maternal undernutrition reprograms reproductive and metabolic phenotypes in female offspring of the rabbit model
(PLOS ONe, 2026) Arias Álvarez, María; Alfonso Gutiérrez-Adan; Eva Pericuesta; Bermejo Álvarez, Pablo; Millán Pastor, María Pilar; María Rodríguez; Lorenzo González, Pedro Luis; Pilar García Rebollar; García García, Rosa María
Maternal undernutrition during pregnancy in mammals can induce long-term effects in offspring health through molecular programming of the gametes. Using the rabbit model, this study investigates whether maternal food restriction (FR) during the first two-thirds of gestation induces effects on ovarian follicular, oocyte, and early embryo developmental markers in F1 female offspring at the onset of reproductive life. Additionally, body composition, metabolic profile, and growth trajectory from birth to sexual maturity (16 weeks) were assessed to evaluate potential impacts on overall health. Pregnant females (F0) were fed either ad libitum (Control group) or a restricted diet covering 60% of nutritional requirements (FR group). Offspring from both groups were fed ad libitum. Maternal FR had no significant effects on birth weight and survival of progeny, growth trajectory, feed intake or glycemic profile during the juvenile phase. Body weight, body composition, lipid, and glycemic profiles in F1 sexually mature females were similar. However, serum aminotransferase levels were significantly elevated in the F1 females from FR group (P<0.05) Serum anti-Müllerian hormone levels, ovulation rate, apoptosis rate, and in vitro embryo development did not differ between groups. These findings suggest that re-feeding after maternal food restriction can attenuate adverse long-term effects on offspring growth and metabolism, while modulating the expression of genes related to oxidative stress, apoptosis and fatty acid uptake in the oocytes of F1 females. This modulation may reflect the activation of compensatory intracellular mechanisms that support early embryonic development in juvenile females at the onset of their reproductive life
Understanding large localized CP violation in B±-* K±π plus π- using dispersive methods
(Physical Review Letters, 2026) Heuser, L. A.; Reyes Torrecilla, Alba; Hanhart, C.; Kubis, B.; Magalhães, P. C.; Mannel, T.; Peláez Sagredo, José Ramón
We utilize the universality of pion-pion (𝜋⁢𝜋) final-state interactions at small invariant masses to understand the enhanced localized 𝐶⁢𝑃 violation in 𝐵± →𝐾±⁢𝜋+⁢𝜋−, using a dispersive approach. From a fit to the integrated 𝐶⁢𝑃-asymmetry data, we successfully predict the Dalitz-plot kinematic distribution of the asymmetry in the low-energy 𝜋⁢𝜋 region, including the large localized 𝐶⁢𝑃 violation recently observed by LHCb. An essential role is played by the contributions of isospin 2. This formalism, whose parameters have a physical meaning, can be adapted straightforwardly to other systems with 𝐶⁢𝑃 violation enhanced by final-state interactions.
Prospects for dark matter observations in dwarf spheroidal galaxies with the Cherenkov Telescope Array Observatory
(Monthly Notices of the Royal Astronomical Society, 2025) Baquero Larriva, Orlando Andrés; Barrio Uña, Juan Abel; Buces Sáez, J.; Cerviño Cortínez, A.; Contreras González, José Luis; Dinesh, A.; Láinez, M.; López Moya, Marcos; Martín Domínguez, D.; Martinez, O.; Miener, Tjark; Miranda Pantoja, José Miguel; Molina Delicado, M.; Moreno Ramos, A.; Moya Zamanillo, V.; Nieto Castaño, Daniel; Pérez Aguilera, A.; Rosado Vélez, Jaime; Tejedor Álvarez, Luis Ángel
The dwarf spheroidal galaxies (dSphs) orbiting the Milky Way are widely regarded as systems supported by velocity dispersion against self-gravity, and as prime targets for the search for indirect dark matter (DM) signatures in the GeV-to-TeV γ -ray range owing to their lack of astrophysical γ -ray background. We present forecasts of the sensitivity of the forthcoming Cherenkov Telescope Array Observatory (CTAO) to annihilating or decaying DM signals in these targets. An original selection of candidates is performed from the current catalogue of known objects, including both classical and ultrafaint dSphs. For each, the expected DM content is derived using the most comprehensive photometric and spectroscopic data available, within a consistent framework of analysis. This approach enables the derivation of novel astrophysical factor profiles for indirect DM searches, which are compared with results from the literature. From an initial sample of 64 dSphs, eight promising targets are identified – Draco I, Coma Berenices, Ursa Major II, Ursa Minor, and Willman 1 in the North, Reticulum II, Sculptor, and Sagittarius II in the South – for which different DM density models yield consistent expectations, leading to robust predictions. CTAO is expected to provide the strongest limits above ∼10 TeV, reaching velocity-averaged annihilation cross sections of ∼ 5 × 10−25 cm3 s−1 and decay lifetimes up to ∼ 1026 s for combined limits. The dominant uncertainties arise from the imprecise determination of the DM content, particularly for ultrafaint dSphs. Observation strategies are proposed that optimize either deep exposures of the best candidates or diversified target selections.
Evaluation of a program for the deinstitutionalization of homeless youth: Futuro&Co in the community
(International Journal of Social Welfare, 2026) Sánchez Moreno, Esteban; García Burgos, Jorge; De la Fuente Roldán, Iria Noa
Youth homelessness is an increasingly significant social issue in Europe, with individuals aged 18–29 at elevated risk of severe social exclusion. Futuro&Co is a community-based social intervention programme implemented by the FACIAM network in Spain, aiming to promote the autonomy and social inclusion of young people in situations of homelessness (YPSH). This study examined the impact of Futuro&Co on improving community social support, perceived social support, loneliness and self-esteem among YPSH. A longitudinal, quasi-experimental, non-randomised controlled design was employed, involving a test group participating in Futuro&Co and a control group receiving standard homelessness services. Quantitative data were collected at programme entry, midpoint, and conclusion using validated questionnaires. Participants in the test group showed significantly greater improvements in overall community social support (F = 4.06, p = 0.02), particularly in terms of community participation (F = 2.91, p = 0.05) and informal support systems (F = 3.73, p = 0.03). Self-esteem also increased significantly (F = 3.16, p = 0.04), primarily due to reductions in negative self-perception. Although there were no statistically significant differences in overall social support or loneliness, the proportion of intervention participants reporting low social support decreased notably between the midpoint and programme closure. The findings highlight the value of community-based, de-institutionalising approaches for YPSH. By fostering informal relational networks, participation and self-esteem, Futuro&Co supports the reconstruction of social ties and autonomy. However, sustained and structural interventions remain essential to reduce loneliness and consolidate long-term social inclusion.
La transición española en la obra y el pensamiento de Rafael Chirbes: crónica de una traición
(Revista chilena de literatura, 2025) Del Rosal Crespo, Mario
Rafael Chirbes (1949-2015) fue un escritor particular en el panorama literario europeo. Desde una visión de clase de raíces marxistas, retrató de forma cruda y crítica la historia contemporánea de España. Su obra abarca paso a paso las contradicciones de cada etapa desde la Guerra Civil hasta su muerte, mostrando con firmeza, pero sin maniqueísmos, las decepciones sufridas por la clase obrera y el triunfo de la burguesía y sus representantes políticos. En este texto, recuperamos y reivindicamos el valor de la obra de Chirbes como valioso testimonio para comprender mejor lo que realmente fue la transición y cómo prefiguró un capitalismo en España que ha conservado en gran medida el aparato de poder económico, político y social heredado del franquismo.
Detection of RS Oph with LST-1 and modelling of its HE/VHE gamma-ray emission
(Astronomy & Astrophysics, 2025) Alvarez Crespo, N.; Baquero Larriva, A.; Barrio Uña, Juan Abel; Contreras González, José Luis; Lainez, M.; López Moya, Marcos; Mas-Aguilar, A.; Miener, Tjark; Moya Zamanillo, V.; Nieto Castaño, Daniel
Context. The recurrent nova RS Ophiuchi (RS Oph) underwent a thermonuclear eruption in August 2021. In this event, RS Oph was detected by the High Energy Stereoscopic System (H.E.S.S.), the Major Atmospheric Gamma Imaging Cherenkov (MAGIC), and the first Large-Sized Telescope (LST-1) of the future Cherenkov Telescope Array Observatory (CTAO) at very-high gamma-ray energies above 100 GeV. This means that novae are a new class of very-high-energy (VHE) gamma-ray emitters. Aims. We report the analysis of the RS Oph observations with LST-1. We constrain the particle population that causes the observed emission in hadronic and leptonic scenarios. Additionally, we study the prospects of detecting further novae using LST-1 and the upcoming LST array of CTAO-North. Methods. We conducted target-of-opportunity observations with LST-1 from the first day of this nova event. The data were analysed in the framework of cta-lstchain and Gammapy, the official CTAO-LST reconstruction and analysis packages. One-zone hadronic and leptonic models were considered to model the gamma-ray emission of RS Oph using the spectral information from Fermi-LAT and LST-1, together with public data from the MAGIC and H.E.S.S. telescopes. Results. RS Oph was detected at 6.6σ with LST-1 in the first 6.35 hours of observations following the eruption. The hadronic scenario is preferred over the leptonic scenario considering a proton energy spectrum with a power-law model with an exponential cutoff whose position increases from (0.26 ± 0.08) TeV on day 1 up to (1.6 ± 0.6) TeV on day 4 after the eruption. The deep sensitivity and low energy threshold of the LST-1/LST array will allow us to detect faint novae and increase their discovery rate.
La colección correa de la real academia de bellas artes de san fernando. una interesante fuente heráldica
(Emblemata: Revista aragonesa de emblemática, 2020) Francisco Olmos, José María De
En este trabajo se aporta un modelo de trabajo sobre investigación heráldica de una colección descontextualizada de grabados, hoy en la Real Academia de Bellas Artes de San Fernando de Madrid, la Colección Antonio Correa.
Del papel a la piedra. el escudo real de la fachada del colegio de santiago de huesca
(Emblemata: Revista aragonesa de emblemática, 2019) Francisco Olmos, José María De; Garcés Manau, Carlos
En este trabajo se intenta demostrar que los diseños heráldicos no se ajustan a normas rígidas e inamovibles, sino que incluso cuando se trata de los escudos reales puede haber distintos modelos de representación. Y esto lo veremos a través de las portadas heráldicas, comparando las diversas ediciones de la famosa Pragmática de tratamientos y cortesías de 1586, y cómo estas portadas fueron modelo para la realización de armerías en otros soportes, como es el caso del colegio de Santiago de Huesca, que muestra un escudo real en su portada de características muy peculiares y se conseguirá descubrir cuál fue el modelo del mismo.
The axis (C2) from El Sidrón and its implications for Neanderthal upper cervical spine form
(Journal of Human Evolution, 2026) Palancar, Carlos A.; Bastir, Markus; García Martínez, Daniel; García Tabernero, Antonio; Rosas, Antonio
The atlas (C1) and axis (C2), the two first vertebrae of the spine, are key elements of the axial skeleton as they link the skull and the postcranium. As such, several works have focused on this region in earlier hominins (Gómez-Olivencia et al., 2007; Beaudet et al., 2020) and nonhuman Primates (Nalley and Grider-Potter, 2017). However, the study of the upper cervical spine of Neanderthals has been only included in more systematic works (Gómez-Olivencia et al., 2013; Haeusler et al., 2019), with the exception of the study of Palancar et al. (2020b). The latter presented the atlases from El Sidrón (Asturias, Spain) and compared them with other Neanderthals and modern humans, showing differences (see below) between them. The El Sidrón site (Asturias, Spain) has yielded more than 2300 Neanderthal fossils dated to approximately 49,000 years ago (Wood et al., 2013), making it the most complete Neanderthal assemblage known from the Iberian Peninsula (Fortea et al., 2003; Rosas et al., 2006, 2012). The axis from this Spanish site is the main subject of the present study.
Versatile magneto‐dielectric response of epitaxial thin films of the high entropy oxide perovskite Nd(Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)O3
(Advanced Materials, 2026) Capu, Roxana; Thompson, Ryan; Rischau, C. Willem; Cantarino, Marli R.; Marsik, Premysl; Bud'ko, Sergey L.; Biskup Zaja, Nevenko; Varela Del Arco, María; Pashkevich, Yurii G.; Orel, Serhii M.; Prokscha, Thomas; Suter, Andreas; Zhao, Jiangtao; Oji, Ugwumsinachi; Bonura, Marco; Bencok, Peter; Salman, Zaher; Gariglio, Stefano; Bernhard, Christian; Sarkar, Subhrangsu
We report the dielectric and magnetic properties of epitaxial thin films of the high entropy oxide (HEO) perovskite Nd(Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)O3, which orders magnetically below T mag approximate to 190 K. At T >> T mag, the dielectric response reveals a Debye-type frequency dependence with a zero-frequency dielectric constant of approximate to 230-250. The dc bias voltage loops of are reversible but exhibit three distinct peaks centred at zero and finite positive and negative voltage. We provide evidence that the zero-bias peak is governed by the oxygen sublattice while the finite bias peaks originate from cationic dipoles. The maximal response of the latter appears to be shifted to finite bias by a static uncompensated electric field due to a vertical gradient of the oxygen content. Below T mag, this anomalous dielectric response is strongly suppressed, presumably by magnetostriction that counteracts and freezes the ionic displacements. These findings indicate a unique correlation between configurational entropy, dielectric response, and magnetic properties. In combination with a large dielectric strength, it enables a non-hysteretic tuning of the dielectric response of magnetoelectronic devices with multiple parameters like temperature, electric, and magnetic field. This HEO is equally interesting for fundamental studies of competing electric and magnetic orders in strongly disordered materials.
Prospects for γ-ray observations of the Perseus galaxy cluster with the Cherenkov Telescope Array
(2024) Alvarez-Crespo, N.; Barrio Uña, Juan Abel; Contreras González, José Luis; Láinez, M.; López Moya, Marcos; Martinez, O.; Mas-Aguilar, A.; Miener, Tjark; Miranda, J.M.; Morcuende Parrilla, Daniel; Nieto Castaño, Daniel; Rosado Vélez, Jaime; Sinha, Atreyee; Tejedor Álvarez, Luis Ángel; Zamanillo, V.M.
Galaxy clusters are expected to be both dark matter (DM) reservoirs and storage rooms for the cosmic-ray protons (CRp) that accumulate along the cluster’s formation history. Accordingly, they are excellent targets to search for signals of DM annihilation and decay at γ-ray energies and are predicted to be sources of large-scale γ-ray emission due to hadronic interactions in the intracluster medium (ICM). In this paper, we estimate the sensitivity of the Cherenkov Telescope Array (CTA) to detect diffuse γ-ray emission from the Perseus galaxy cluster. We first perform a detailed spatial and spectral modelling of the expected signal for both the DM and the CRp components. For each case, we compute the expected CTA sensitivity accounting for the CTA instrument response functions. The CTA observing strategy of the Perseus cluster is also discussed. In the absence of a diffuse signal (non-detection), CTA should constrain the CRp to thermal energy ratio X500 within the characteristic radius R500 down to about X500 < 3 × 10−3, for a spatial CRp distribution that follows the thermal gas and a CRp spectral index αCRp = 2.3. Under the optimistic assumption of a pure hadronic origin of the Perseus radio mini-halo and depending on the assumed magnetic field profile, CTA should measure αCRp down to about ∆αCRp ≃ 0.1 and the CRp spatial distribution with 10% precision, respectively. Regarding DM, CTA should improve the current ground-based γ-ray DM limits from clusters observations on the velocity-averaged annihilation cross-section by a factor of up to ∼ 5, depending on the modelling of DM halo substructure. In the case of decay of DM particles, CTA will explore a new region of the parameter space, reaching models with τχ > 1027 s for DM masses above 1 TeV. These constraints will provide unprecedented sensitivity to the physics of both CRp acceleration and transport at cluster scale and to TeV DM particle models, especially in the decay scenario.
Future prospects of gene therapy for Friedreich’s Ataxia
(International Journal of Molecular Sciences, 2021) Ocaña Santero, Gabriel; Díaz Nido, Javier; Herranz Martín, Saúl
Friedreich’s ataxia is an autosomal recessive neurogenetic disease that is mainly associated with atrophy of the spinal cord and progressive neurodegeneration in the cerebellum. The disease is caused by a GAA-expansion in the first intron of the frataxin gene leading to a decreased level of frataxin protein, which results in mitochondrial dysfunction. Currently, there is no effective treatment to delay neurodegeneration in Friedreich’s ataxia. A plausible therapeutic approach is gene therapy. Indeed, Friedreich’s ataxia mouse models have been treated with viral vectors en-coding for either FXN or neurotrophins, such as brain-derived neurotrophic factor showing promising results. Thus, gene therapy is increasingly consolidating as one of the most promising therapies. However, several hurdles have to be overcome, including immunotoxicity and pheno-toxicity. We review the state of the art of gene therapy in Friedreich’s ataxia, addressing the main challenges and the most feasible solutions for them.
Glial cell activation precedes neurodegeneration in the cerebellar cortex of the YG8–800 murine model of Friedreich ataxia
(Neurobiology of Disease, 2024) Vicente Acosta, Andrés; Herranz Martín, Saúl; Pazos, María Ruth; Galán Cruz, Jorge; Amores, Mario; Loria, Frida; Díaz Nido, Javier
Friedreich ataxia is a hereditary neurodegenerative disorder resulting from reduced levels of the protein frataxin due to an expanded GAA repeat in the FXN gene. This deficiency causes progressive degeneration of specific neuronal populations in the cerebellum and the consequent loss of movement coordination and equilibrium, which are some of the main symptoms observed in affected individuals. Like in other neurodegenerative diseases, previous studies suggest that glial cells could be involved in the neurodegenerative process and disease progression in patients with Friedreich ataxia. In this work, we followed and characterized the progression of changes in the cerebellar cortex in the latest version of Friedreich ataxia humanized mouse model, YG8–800 (Fxnnull:YG8s(GAA)>800), which carries a human FXN transgene containing >800 GAA repeats. Comparative analyses of behavioral, histopathological, and biochemical parameters were conducted between the control strain Y47R and YG8–800 mice at different time points. Our findings revealed that YG8–800 mice exhibit an ataxic phenotype characterized by poor motor coordination, decreased body weight, cerebellar atrophy, neuronal loss, and changes in synaptic proteins. Additionally, early activation of glial cells, predominantly astrocytes and microglia, was observed preceding neuronal degeneration, as was increased expression of key proinflammatory cytokines and downregulation of neurotrophic factors. Together, our results show that the YG8–800 mouse model exhibits a stronger phenotype than previous experimental murine models, reliably recapitulating some of the features observed in humans. Accordingly, this humanized model could represent a valuable tool for studying Friedreich ataxia molecular disease mechanisms and for preclinical evaluation of possible therapies.
Hypernatremia in Hospital-at-Home Patients: Prevalence, Clinical Profile, and Mortality in Institutionalized and Home-Dwelling Older Adults
(Journal of Clinical Medicine, 2026) De Castro García, María; Nuñez Palomares, Sara; Anton Santos, Juan Miguel; Estrada Santiago, Alejandro; Majo Carbajo, Yolanda; García de la Torre Rivera, Pilar; García Sánchez, Francisco Javier; Cubo Romano, Pilar
Background: Hypernatremia is an infrequent but clinically relevant electrolyte disorder in older adults and is associated with poor outcomes. Patients managed through Hospital-at-Home (HaH) programs, particularly those living in institutional settings, are especially vulnerable due to functional dependency and cognitive impairment. Evidence regarding the prevalence and prognostic impact of hypernatremia in HaH settings remains limited. Methods: We conducted a retrospective observational cohort study including all patients admitted to a Hospital-at-Home unit between 2019 and 2024. Patients were classified according to care setting as home-dwelling or institutionalized. Hypernatremia was defined as a serum sodium concentration >145 mmol/L. Sociodemographic, functional (Barthel Index), and cognitive (Global Deterioration Scale) variables were collected. Mortality during HaH admission and at 30, 60, and 90 days was analyzed, and survival was assessed using Kaplan–Meier methods. Results: A total of 4501 patients were included, of whom 2701 were treated at home and 1800 in institutional settings. Hypernatremia was significantly more prevalent among institutionalized patients than among home-dwelling patients (3.1% vs. 0.8%, p < 0.001). Institutionalized patients with hypernatremia showed greater functional dependency (Barthel Index 11 vs. 15, p = 0.041) and more advanced cognitive impairment (GDS 6 vs. 5.5, p = 0.033) compared with those without hypernatremia. Mortality among institutionalized patients with hypernatremia was high, reaching 32.9% during HaH admission, 61.2% at 30 days, 70.6% at 60 days, and approximately 79% at 90 days. Kaplan–Meier analysis demonstrated a rapid decline in survival during the first month following diagnosis. Conclusions: In Hospital-at-Home programs, hypernatremia is more prevalent among institutionalized older adults and is strongly associated with severe functional and cognitive impairment and very high short- and medium-term mortality. These findings suggest that hypernatremia should be considered a marker of advanced frailty rather than an isolated electrolyte disturbance.

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