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A compact group lens modeled with GIGA-Lens: Enhanced inference for complex systems
No full textContext. In the era of large-scale astronomical surveys, the fast modeling of strong lens systems has become increasingly vital. While significant progress has been made for galaxy-scale lenses, the development of automated methods for modeling larger systems, such as groups and clusters, is not as extensive., Aims. Our study aims to extend the capabilities of the GIGA-Lens code, enhancing its efficiency in modeling multi-galaxy strong lens systems. We focus on demonstrating the potential of GPU-accelerated Bayesian inference in handling complex lensing scenarios with a high number of free parameters., Methods. We employed an improved inference approach that combines image position and pixelated data with an annealing sampling technique to obtain the posterior distribution of complex models. This method allowed us to overcome the challenges of limited prior information, a high number of parameters, and memory usage. We validated our process through the analysis of the compact group lens system DES J0248-3955 and we present the relevant VLT/X-shooter spectra., Results. We measured a redshift of z = 0.69 +/- 0.04 for the group, and z = 1.2722 +/- 0.0005 for one of the extended arcs. Our enhanced method successfully constrained a lens model with 29 free parameters and lax priors in a remarkably short time. The mass of the lens is well described by a single dark-matter halo with a velocity dispersion of sigma(v) = (690 +/- 30) km s(-1). The model predicts the presence of a second source at the same redshift and a third source at approximately z similar to 2.7., Conclusions. Our study demonstrates the effectiveness of our lens modeling technique for dealing with a complex system in a short time using ground-based data. This presents a considerable prospect within the context of large surveys, such as LSST, in the future.ANID/FONDECYT; Folio de beca: FB210003 y 2305031
Nonpharmacological interventions to promote sleep in the adult critical patients unit: a scoping review
No full textBackground: Sleep and circadian rhythms are markedly altered in intensive care unit (ICU) patients. Numerous factors related to the patient and the ICU environment affect the ability to initiate and maintain sleep. Therefore, nonpharmacological interventions could play an essential role in improving sleep and circadian rhythm. Objective: The aim of this study was to examine nonpharmacological interventions evaluated for promoting sleep in adult ICUs. Methods: A scoping review was conducted, including randomised controlled trials, nonrandomised controlled trials, quasi-experimental trials, and other controlled studies investigating the effects of nonpharmacological interventions promoting sleep in adult ICU patients. Results: A total of 57 articles and 14 ongoing trials were included in the review, of which 38 were randomised clinical trials. Nine nonpharmacological interventions to improve sleep in critically ill patients were evaluated: earplugs and/or eye masks, aromatherapy, bundles, music intervention, massage or acupressure, noise masking, bright light, and dynamic light. Most included trials simultaneously assessed the effect of more than one intervention on perceived sleep quality using questionnaires. The association between the interventions and improved sleep varied. In the case of multicomponent interventions, it is difficult to identify which components might have influenced sleep improvement. Conclusions: Numerous studies have evaluated various nonpharmacological interventions to promote sleep in critically ill patients, several of which improved perceived sleep quality. However, the substantial variability of the assessed interventions and their implementation complicates drawing reliable conclusions. Registration: The protocol for this scoping review was registered with the Open Science Framework under the identifier https://doi.org/10.17605/OSF.IO/MPEQ5.ANID FONDECYT No. 1201772Research Department of the School of Nursing of the Pontifiicia Universidad Católica de Chil
Management of alcohol use disorder: a gastroenterology and hepatology-focused perspective
No full textAlcohol use disorder is a prevalent and major but preventable cause of morbidity and mortality worldwide, causing several important health consequences, including chronic liver disease. Despite its substantial effects, most clinicians do not adequately assess alcohol intake in clinical practice, and there are several barriers to providing integrated management to patients with alcohol use disorder. Standardised questionnaires, such as the Alcohol Use Identification Test (AUDIT), can facilitate the identification of individuals at risk of alcohol use disorder, and alcohol biomarkers such as phosphatidylethanol aid in quantifying levels of alcohol consumption. Non-pharmacological interventions—including brief interventions, twelve-step facilitation, motivational enhancement therapy, contingency management, and cognitive behavioural therapy—are effective for patients with alcohol use disorder, regardless of the presence of advanced liver disease. Pharmacological treatments should be considered according to the severity of liver disease and other comorbidities, safety profile, and local availability. The management of patients with alcohol use disorder and associated liver disease should ideally be performed in the setting of integrated multidisciplinary teams
Long Lived Heavy Neutral Leptons from Z' decays at FCC-ee
No full textTesis (Master’s degree in Physics)--Pontificia Universidad Católica de Chile, 2025Westudy the phenomenology of a U(1)B−L extension of the Standard Model (SM) predicting long-lived heavy neutral leptons (HNLs), which are pair produced from a new gauge boson Z’ with displaced vertex signatures at the electron positron mode of the Future Circular Collider (FCC-ee). Progress on sensitivity prospects are provided in the 1-100GeV mass scale for the B-L gauge coupling g′ = 10−3 and 10−4, and HNL-light neutrino mixing |VµN|2 = 10−8 − 10−20, a region that has not been constrained by the Large Hadron Collider (LHC). Exclusion curves are obtained for a configuration of the IDEA detector with and without a LAYCAST-like far detector on the HNL vs Z’ mass plane (MN −MZ′) and the HNLmass vs heavy-light squared neutrino mixing plane (MN − |VµN|2
Long-lived particle phenomenology in one-loop neutrino mass models with dark matter
No full textNeutrino masses and dark matter (DM) might have a common origin. The scotogenic model can be considered the proto-type model realizing this idea, but many other variants exist. In this paper we explore the phenomemology of a particular DM neutrino mass model, containing a triplet scalar. We calculate the relic density and check for constraints from direct detection experiments. The parameter space of the model, allowed by these constraints, contains typically a long-lived or quasi-stable doubly charged scalar, that can be searched for at the LHC. We reinterpret existing searches to derive limits on the masses of the scalars of the model and estimate future sensitivities in the high-luminosity phase of the LHC. The searches we discuss can serve to constrain also many other 1-loop neutrino mass models
Strategies for fire-fighting in underventilated compartments: Reducing the likelihood and severity of a potential backdraught
No full textFires in underventilated compartments remain an unresolved problem for fire brigades. While some brigades have specific guidance in place regarding procedures for approaching and fighting such fires, this guidance is, for the most part, based on anecdotal evidence, having been instigated following historical incidents involving fire-fighter injuries or fatalities. As fire-fighters open a door or window to an under-ventilated compartment fire, there is a risk of a sudden fire development that may come in the form of a rapid flare up or backdraught. A programme of reduced scale fire experiments was designed to obtain deeper insight into this phenomenon. The results of these experiments are presented showing the conditions under which changes in the ventilation conditions of an underventilated compartment were beneficial for firefighting activities and under which conditions this was detrimental. This paper provides further scientific understanding of the fire dynamics in underventilated compartments when changes in ventilation conditions occur. The use of ventilation tactics, preceded by strict safety precautions and comprehensive tactical considerations, appears to be a practical solution that reduces the likelihood and severity of a potential backdraught. The results presented could be used to develop simple guidance, which may be used in fire brigade practice, to decide when and how to intervene in this kind of fires
Reinforcement Effects and Parametric Study of the Lateral Response of Multilayered Wood-Frame Shear Walls: An Experimental and Numerical Investigation
No full textIn the seismic design of light-frame timber buildings (LFTBs), the use of strong shear walls (SSWs) is crucial for providing lateral resistance. While the contribution of finish layers, such as Type X gypsum wallboard (GWB), has generally been conservatively ignored, recent experimental and numerical studies have demonstrated that these finish layers can significantly enhance the cyclic lateral performance of SSWs, leading to the concept of multilayered strong shear walls (MLSSWs). The effect of the finish layers cannot be solely attributed to additional layers and fasteners. There is also an additional reinforcement effect from deeply screwed Type X GWB that prevents nails from pulling out during hysteresis cycles that has not been previously investigated. The primary objective of this study is to explore the reinforcement effect and evaluate MLSSWs across a broad range of configurations. The research combines experimental tests (monotonic and cyclic) and numerical simulations, with connection-level tests used to calibrate the numerical models. The simulations interrogate the influence of the reinforcement effect and investigate the effects of various parameters, including wall aspect ratio, number of Type X GWB layers, multilayered connection type (screwed or stapled), and overturning anchorage systems. The findings demonstrate the positive effect of finish layers on strength and stiffness. The reinforcement effect of screws and Type X GWB layers is shown to modify the response of nailed OSB-to-frame connections, preventing nail pullout and improving fatigue resistance and deformation capacity. The study shows that the other important parameters that control the strength, stiffness and deformation capacity of MLSSW are multilayered connection type and number of Type X GWB layers. This research enhances the understanding of the role of Type X GWB finish layers on the lateral response of MLSSWs for improved design and construction.CONICYT (Doctorado Nacional 2018–21180074) VRI-UC; ANID BASAL; No. FB210015 (CENAMAD); Research Center for Integrated Disaster Risk Management (CIGIDEN); ANID/FONDAP; No. 1511001
Manual para familiares (o cuidadores) de personas con Trastorno de Personalidad
No full textManual Psicoeducativo que tiene como objetivo dar información a aquellas personas que cuidan y/o acompañan a algún ser querido con trastorno de personalidad. Este trabajo se enmarca dentro de una colaboración entre la Escuela de Psicología UC y la fundación PsiConecta, con el apoyo de MIDAP
Lepton universality in the MSSM with trilinear R-parity violation model
No full textTesis (Master’s degree in Physics)--Pontificia Universidad Católica de Chile, 2024The Standard Model (SM) of particle physics, though highly successful, fails to address several fundamental questions, including the neutrino masses origin, the nature of dark matter, among others. The recent LHCb collaboration analysis measured the ratio of branching fractions RK inB+ → K+ℓ+ℓ− decay to test lepton universality, a property predicted by the SM. This observable is particularly powerful due to the cancellation of hadronic uncertainties, making it a sensitive probe for new physics. The measured value of RK is consistent with the SM prediction, suggesting nosignificant lepton universality violation. Nevertheless, given the limitations of the SM, this thesis explores a SM extension using the MSSM+λ ′TRPV model. By incorporating all possible SUSY contributions, we aim to theoretically predict the experimental RK result, providing a novel perspective on determining the parameter space that fit with the experimental measurement. The analysis is conducted within an Effective Field Theory framework across four different scenarios for Wilson Coefficients to account for the higher energy scales associated with these particles, translating their effects to the measurable energy range. The theoretical calculation is performedusing a scan in Python, while respecting other experimental constraints regarding SUSY particles. We found that the parameter space that respect the 3σ region of the LHCb collaboration measurement is |λ′| ≲ 10−2 or m˜ ≳ 8.5 TeV. Additionally, we found that our result is independent from each scenario for Wilson Coefficients. Finally, we discovered that RK has no particular bias towards any individual λ′ijk.Instituto Milenio de Física Subatómica en la Frontera de Altas Energías (SAPHIR); Pontificia Universidad Católica de Chil
Dysregulated ATX-LPA and YAP/TAZ signaling in dystrophic Sgcd−/− mice with early fibrosis and inflammation
No full textBackground Sarcoglycanopathies are muscle dystrophies caused by mutations in the genes encoding sarcoglycans (α, β, γ, and δ) that can destabilize the dystrophin-associated glycoprotein complex at the sarcolemma, leaving muscle fibers vulnerable to damage after contraction, followed by inflammatory and fibrotic responses and resulting in muscle weakness and atrophy. Two signaling pathways have been implicated in fibrosis and inflammation in various tissues: autotaxin/lysophosphatidic acid (ATX-LPA) and yes-associated protein 1/transcriptional co-activator with PDZ-binding motif (YAP/TAZ). LPA, synthesized by ATX, can act as a pleiotropic molecule due to its multiple receptors. Two Hippo pathway effectors, YAP/TAZ, can be dephosphorylated by LPA and translocated to the nucleus. They induce several target genes, such as CCN2/CTGF, involved in fibrosis and inflammation. However, no detailed characterization of these processes or whether these pathways change early in the development of sarcoglycanopathy has been evaluated in skeletal muscle. Methods Using the δ-sarcoglycan knockout mouse model (Sgcd−/−), we investigated components of these pathways, inflammatory and fibrotic markers, and contractile properties of different skeletal muscles (triceps-TR, gastrocnemius-GST, diaphragm-DFG, tibialis anterior-TA, and extensor digitorum longus-EDL) at one and two months of age. Results We found that Sgcd−/− mice show early dystrophic features (fiber damage/necrosis, centrally nucleated fibers, inflammatory infiltrate, and regenerated fibers) followed by later fiber size reduction in TR, GST, and DFG. These changes are concomitant with an early inflammatory and fibrotic response in these muscles. Sgcd−/− mice also have early impaired force generation in the TA and EDL, and resistance to mechanical damage in the EDL. In addition, an early dysregulation of the ATX-LPA axis and the YAP/TAZ signaling pathway in the TR, GST, and DFG was observed in these mice. Conclusions The ATX-LPA axis and the YAP/TAZ signaling pathway, which are involved in inflammation and fibrosis, are dysregulated in skeletal muscle from an early age in Sgcd−/− mice. These changes are concomitant with a fibrotic and inflammatory response in these mice. Unraveling the role of the LPA axis and YAP/TAZ in sarcoglycanopathy holds great promise for improving our understanding of disease pathogenesis and identifying novel therapeutic targets for this currently incurable group of muscle disorders