The University of the Republic (Spanish: Universidad de la República, sometimes UdelaR) is Uruguay's oldest public university. It is by far the country's largest university, as well as the second largest public university in South America and the world's 57th largest by enrollment, with a student body of 137,757 undergraduate students in 2018 and 6,351 postgraduate students in 2012. It was founded on 18 July 1849 in Montevideo, where most of its buildings and facilities are still located. Its current rector is Rodrigo Arim.
The development of cleaner and more efficient combustion systems is essential to reduce the environmental impact of transportation and to integrate renewable fuels into future energy strategies. Understanding how combustion dynamics change under diluted conditions is crucial for improving efficiency and reducing emissions of carbon monoxide, unburned hydrocarbons, and nitrogen oxides. In this context, the present research investigates the influence of flame propagation speed on the combustion of ethanol, isooctane, and gasoline mixed with ethanol in a spark ignition optical research engine. Two dilution strategies were examined: combustion with excess air and with a synthetic mixture of carbon dioxide and nitrogen representing exhaust gas recirculation. High-speed optical diagnostics and thermodynamic analysis were combined to correlate flame development with engine performance, combustion stability, and gaseous emissions. The results show that moderate dilution enhances efficiency until the flame speed falls below twenty meters/second and combustion ends forty-five degrees after the upper dead center. Exhaust gas dilution strongly decreases nitrogen oxide formation, while air dilution promotes faster combustion and lower carbon monoxide emissions. The study demonstrates the central role of flame propagation speed in linking combustion efficiency, stability, and emissions, providing guidance for the design of engines operating with renewable and blended fuels.
In this work, we present two Nitsche-based mixed finite element methods. The first one concerns the scalar Poisson problem on a domain whose boundary is partitioned into Dirichlet and Neumann (linear) conditions. For this problem, we introduce a new discrete variational formulation that enables the weak imposition of mixed boundary conditions. The proposed method is analyzed within the Babu & scaron;ka-Brezzi framework, ensuring the well-posedness of the discrete problem. We derive optimal apriori error estimates and present numerical experiments that confirm the theoretical convergence rates and demonstrate the robustness of the proposed scheme. The second method is a mixed Nitsche-type discretization for the unilateral (non-linear) Signorini conditions in the scalar case, as a simple prototype for contact and friction problems or other variational inequalities associated with boundary conditions. We present the full variational formulation. The performance of the method is assessed by numerical experiments that illustrate the accurate enforcement of the boundary conditions and the expected behavior under mesh refinement.
Methotrexate (MTX) is a long-standing drug used to treat leukemia (at high doses to inhibit DNA/RNA synthesis) and rheumatoid arthritis (at low doses for anti-inflammatory effects). Its characteristic narrow therapeutic range, in terms of efficacy and safety associated with MTX, are important factors to consider when deciding whether to prescribe it. A major challenge in its use is interindividual variability which is largely attributed to germline genetic polymorphisms in genes encoding proteins that control the pharmacokinetics or pharmacodynamics of MTX. This study updates a previous 2018 review using a systematic literature search in PubMed/MEDLINE, Scopus, and SciELO. The search, conducted according to the PRISMA protocol, employed predefined keywords to identify studies published up to June 2025. This systematic review identified that, to date, only a few genetic polymorphisms influence clinical decision-making. Specifically, the MTHFR 677T allele and the MTHFR 677T–1298 A haplotype (rs1801133- rs1801131) have been associated with toxicity in both adults and children. Furthermore, the 677T–1298 A haplotype has been linked with reduced event-free survival in Caucasian patients with either adult RA or pediatric ALL. Regarding other markers, the TYMS rs34743033 3R allele has been implicated with reduced efficacy in adult patients receiving low-dose MTX, while the FPGS rs1544105 T allele has shown an association with diverse toxicities in ALL pediatric patients. Although considerable research has been conducted and numerous results have been obtained, the available evidence remains predominantly of moderate quality. Consequently, current guidelines from CPIC and the DPWG do not recommend routine MTX dose adjustments based solely on single gene variants. It is, therefore, imperative to develop and validate multifactorial risk prediction tools that integrate a range of other clinical factors. Accordingly, the establishment of a comprehensive pharmacogenetics-guided dosing guideline for MTX remains an elusive goal.
Postpartum estrous (PPE) rats are able to care for their litter and copulate with a male, however when given the choice, they prefer their pups over males. This preference is stronger in multiparous rats than in primiparous rats, indicating that previous reproductive experience increases their maternal motivation. Dopaminergic neurotransmission, particularly that acting on D1-like receptors in the Nucleus Accumbens (NAcc) and the medial Preoptic Area (mPOA), has been implicated in controlling maternal motivation and maternal behavior execution. Determining whether the dopaminergic system differs between primiparous and multiparous PPE rats. Two approaches were employed: 1) determining the effect of systemic administration of the selective D1-like receptors antagonist SCH-23390 (at 0.0, 0.025, and 0.05 mg/kg doses) on maternal behavior execution and locomotion, and 2) determining D1- and D2-like receptors binding in the NAcc, dorsal striatum, medial prefrontal cortex, and mPOA of primiparous and multiparous PPE rats. SCH-23390 reduced the active components of maternal behavior and locomotor activity in PPE rats, with the lower dose of this D1-like receptors antagonist having greater effects in multiparous females. Compared to primiparous females, multiparous rats also exhibited increased binding to the D1-like receptors antagonist [3H]-SCH-23390 in NAcc and dorsal striatum and reduced binding to the D2-like receptors antagonist [3H]-nemonapride in the NAcc shell. These findings demonstrate that prior reproductive experience alters the behavioral sensitivity to SCH-23390 and its binding in the striatum of PPE rats.
The western Antarctic Peninsula is characterized by pronounced climate variability and a high concentration of human activities, including tourism and fishing. The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), the body responsible for the conservation of Antarctic marine ecosystems and for regulating fisheries south of the Antarctic Convergence, considers Pygoscelis penguins to be key ecosystem indicator species. In this study, we used stomach content analysis and tracking data to examine diet composition and foraging parameters of chinstrap (Pygoscelis antarcticus) and gentoo (Pygoscelis papua) penguins breeding in two colonies at Cierva Cove, Gerlache Strait (64°08′ S, 60°59′ W and 64°10′ S, 60°56′ W, respectively). Our aim was to identify their main prey and the areas they use during foraging trips in the chick-rearing period of the 2024/25 breeding season. Antarctic krill (Euphausia superba) dominated the diet of both species; however, chinstrap penguins consumed smaller krill than gentoo penguins. Tracking data showed that both species foraged in coastal areas, with chinstrap penguins undertaking shorter trips, both distance and duration than their congeners. This study provides updated, spatially explicit ecological information to support management and conservation in the Gerlache Strait, a region increasingly pressured by krill fisheries.
