186698 research outputs found
Sort by
Understanding the Role of Cognitive Abilities and Math Anxiety in Adolescent Math Achievement
No full textA consistent amount of research has tried to study the contributions of cognitive and emotional factors involved in math achievement. Despite this, research examining their joint role in children is scarce. In this paper, we examined the joint role of cognitive and math anxiety on math achievement in a sample of 135 seventh-grade children (54% male, M-age = 12.79, SD = 0.47). Math achievement was measured using a validated paper-and-pencil test, while higher-order cognitive abilities were assessed with a PMAs test. Working memory was evaluated through two verbal and two visuo-spatial experimental span tasks. Inhibitory control was measured using three computerized tasks adapted from the classic Stroop, Flanker, and Simon tasks. Math anxiety was assessed with an AMAS questionnaire. A series of correlation analyses and path models were conducted to understand the complex relationships among the factors. The correlations showed a positive relationship among our cognitive abilities and a negative correlation with math anxiety. The results from the path analysis showed a strong effect of higher-order cognitive abilities on math achievement (beta = 0.44, p < .001) and highlighted the mediating role of working memory between math anxiety and math performance (beta = -0.04, 95%CI [-0.11; -0.00]). Conversely, inhibitory control did not seem to play a crucial role in this relationship (beta = -0.03, 95%CI [-0.08; 0.00]). These findings are discussed in relation to current theoretical frameworks. Interventions aimed at reducing math anxiety could help improve math achievement
A Simplified Fish School Search Algorithm for Continuous Single-Objective Optimization
No full textThe Fish School Search (FSS) algorithm is a metaheuristic known for its distinctive
exploration and exploitation operators and cumulative success representation approach. Despite its success across various problem domains, the FSS presents issues due to its high number of parameters, making its performance susceptible to improper parameterization. Additionally, the interplay between its operators requires a sequential execution in a specific order, requiring two fitness evaluations per iteration for each individual. This operator’s intricacy and the number of fitness evaluations pose the issue of costly fitness functions and inhibit parallelization. To address these challenges, this paper proposes a Simplified Fish School Search (SFSS) algorithm that preserves the core features of the original FSS while redesigning the fish movement operators and introducing a new turbulence mechanism to enhance population diversity and robustness against stagnation. The SFSS also reduces the number of fitness evaluations per iteration and minimizes the algorithm’s parameter set. Computational experiments were conducted using a benchmark suite from the CEC 2017 competition to compare the SFSS with the traditional FSS and five other well-known metaheuristics. The SFSS outperformed the FSS in 84% of the problems and achieved the best results among all algorithms in 10 of the 26 problems
Multisource methodology for traffic analysis zone definition based on the fusion of Remote Sensing, OpenStreetMap, and Floating Car Data
No full textAntibacterial Activity of Plectranthus scutellarioides Leaf Against Actinomyces viscosus and Biocompatibility Testing on hFOB 1.19 Cell Line
No full textCerebrospinal fluid analysis and changes over time in patients with subarachnoid hemorrhage: a prospective observational study
No full textBackgroundChanges in cerebrospinal fluid (CSF) in patients with aneurysmal subarachnoid hemorrhage (aSAH) have not been fully elucidated, yet they are critical and may potentially be associated with the risk of complications. The aim of this study is to characterize the biochemical properties of CSF and examine the temporal changes in aSAH patients with and without post-aSAH complications such as vasospasm and shunt-dependent hydrocephalus. MethodsThis prospective observational longitudinal cohort study involved collecting CSF and arterial blood samples from SAH patients requiring an external ventricular drain at four different timepoints following the initial event (1-3, 4-7, 8-13, and 14-20 days after aSAH). A control group that comprised patients with idiopathic normal pressure hydrocephalus undergoing CSF sampling was included. ResultsA total of 20 SAH patients and 20 controls were enrolled. We observed significantly higher levels of hemoglobin (Hb), proteins, lactate, and cell concentrations in the CSF of aSAH patients compared to the control group (p < 0.001), with no corresponding differences in serum levels. Furthermore, a progressive decline in CSF Hb, proteins, and cells levels was noted over the days following the hemorrhage (p = 0.029, p = 0.005, and p = 0.010, respectively). Patients that developed vasospasm exhibited a lower CSF glucose/lactate ratio (p < 0.001) and reduced CSF sodium levels (p = 0.045), while patients that developed shunt-dependent hydrocephalus exhibited higher plasmatic and CSF glucose levels (p = 0.013 and p = 0.003, respectively) and lower CSF Hb/proteins ratio (p < 0.001). ConclusionsPatients with aSAH exhibit changes in the biochemical profile of the CSF, which evolve over time following the acute event. Parameters such as CSF glucose/lactate ratio and CSF Hb/proteins ratio could potentially provide valuable insights not only into the pathophysiology of aSAH but also into patient risks of post-hemorrhagic complications, such as vasospasm and hydrocephalus
Inorganic Nanomaterials Meet the Immune System: An Intricate Balance
No full textThe immune system provides defense against foreign agents that are considered harmful for the organism. Inorganic nanomaterials can be recognized by the immune system as antigens, inducing an immune reaction dependent on the patient's immunological anamnesis and from several factors including size, shape, and the chemical nature of the nanoparticles. Furthermore, nanomaterials-driven immunomodulation might be exploited for therapeutic purposes, opening new horizons in oncology and beyond. In this scenario, we present a critical review of the state of the art regarding the preclinical evaluation of the effects of the most promising metals for biomedical applications (gold, silver, and copper) on the immune system. Because exploiting the interactions between the immune system and inorganic nanomaterials may result in a game changer for the management of (non)communicable diseases, within this review we encounter the need to summarize and organize the plethora of sometimes inconsistent information, analyzing the challenges and providing the expected perspectives. The field is still in its infancy, and our work emphasizes that a deep understanding on the influence of the features of metal nanomaterials on the immune system in both cultured cells and animal models is pivotal for the safe translation of nanotherapeutics to the clinical practice
Crystallization of Polycaprolactone within Nanopapers Based on Graphene-Related Materials
No full textThe crystallization of polymers in nanopapers based on graphene-related materials (GRMs) influences both elastic deformability and heat transfer within the nanostructure. Polycaprolactone (PCL) crystallizes in nanopapers, producing different crystalline fractions. We relate their formation to the interactions between polymer chains and the surface of GRM. In addition to conventional PCL crystals, we observe higher melting point crystals that result from strong heterogeneous nucleation, as well as crystals that melt above PCL’s equilibrium melting temperature, seemingly linked to the prewetting of crystalline layers. The relative intensity of various melting peaks depends on the structural features and defects of GRM and the nanopaper preparation process. The molecular weight of PCL affects the thermal stability of crystals that melt above PCL’s equilibrium melting temperature. Notably, these high-stability crystals cannot be thermally fractionated by successive self-nucleation and annealing (SSA), nor can they be dissolved in a conventional solvent for PCL, indicating a particularly strong interaction between PCL and GRM in nanopapers, which might be utilized in other hybrid organic-inorganic nanostructures
Pressure Gain Combustion propulsion application with part load and dynamic analysis
No full textAerospace propulsion systems utilizing gas turbines have been in use for nearly a century. The staggering amount of technological advancements made in improving the efficiency and performance of gas turbines have resulted in some of the best examples of human ingenuity. Unfortunately, the conventional gas turbines are reaching the limits of their performance, and this warrants innovative concepts to respond to the ever-increasing performance requirements. Pressure Gain Combustion is such a technology that has gained momentum in the recent decades, with advantages such as higher thermodynamic cycle efficiency and lower specific fuel consumption. The propulsion devices based on PGC also support the use of hydrogen fuel, making them attractive to a carbon neutral global trend. But this technology is yet to be realized in aeronautical propulsion sector.
In this thesis, the application of Pressure Gain Combustion for aeronautical propulsion is studied. The study has resulted in dynamic modelling of aircraft engines with/without PGC technology, along with part load performance evaluation. In addition, the research work also resulted in the development of dynamic models that can be applied both standalone open-loop compression systems & closed-loop compression systems for heat pumps, and reduced order modelling methodology for rotating detonation combustion. A simple bleed scheduler system for PGC aircraft engines is also developed during the research thesis, which would assist in the component level development studies of PGC aircraft engines in the future
Biomimetic hybrid vesicles for colorectal cancer targeting
No full textThe functionalization of nanosystems with cell-derived materials has been proposed as a promising strategy for targeted drug delivery. This approach combines high colloidal stability and low rate of clearance from the reticuloendothelial system, with a controlled preparation process. In this work, colorectal cancer cells from a murine cell line (CT26 cells) were used as cell membrane (CM) source for the preparation of biomimetic nanosystems intended for cancer cells targeting. The purification from residual genetic material from parent cells was assessed in the CM fraction and the retained protein profile was studied. CT26 CM were used to prepare vesicles, and combined with synthetic lipids at different protein:lipid ratios to obtain hybrids. CM and lipids were hybridized using two techniques: co-extrusion and hydrodynamic mixing using microfluidics. The obtained formulations were compared in terms of physicochemical properties, protein content and membrane hybridization. The insertion of artificial phospholipids in hybrid vesicles enabled to improve the production yield. The internalization and selectivity of biomimetic vesicles into parent cells compared to different cell types was assessed in vitro, likewise their biocompatibility in 2D and 3D cell cultures. The obtained results demonstrated that purified and stable bio-inspired nanosystems were developed with high throughput, evidencing the superiority of microfluidics in terms of material conservation and process standardization. Moreover, significantly improved cellular uptake of the developed systems was observed when compared to artificial liposomes, reaching the highest value in the homotypic internalization to parent cells