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This investigation studied numerically the aerodynamical effects of different modifications in a model of a common sedan. Four car modifications as spoiler, wing profile spoiler, standard diffuser and curved diffuser and their combinations were reported. Using a three-dimensional sedan model created with Computer-Aided Design software, the modifications are applied and assessed their influence on aerodynamics at speeds ranging from 60 to 120 km/h. The spoiler, wing spoiler, standard diffuser and curved diffuser reducing the lift forces experienced by the vehicle. Three cases, spoiler, wing spoiler, and curved diffuser increase the drag forces Combining a curved diffuser and a spoiler significantly decreases lift forces by an average of 77.8%, albeit with a 15.3% increase in drag forces, by 120 km/h The synergy of a curved diffuser and a wing spoiler achieves a substantial 63.3% reduction of net vertical forces, with only a 7.9% increase in drag forces, by 120 km/h, offering improved control with lesser energy consumption in comparison to other combinations. Results show that modifications, greatly influence airflow interaction, with effects varying by speed. Importantly, the impact of using two modifications is not a simple sum of their individual effects; and it must be assessed thoughtfully alongside airflow alterations. [ABSTRACT FROM AUTHOR]

Background: Venereal syphilis, caused by the spirochete Treponema pallidum subsp. pallidum (TPA), is surging worldwide, underscoring the need for a vaccine with global efficacy. Vaccine development requires an understanding of syphilis epidemiology and clinical presentation as well as genomic characterization of TPA strains circulating within at-risk populations. The aim of this study was to describe the clinical, demographic, and molecular features of early syphilis cases in Cali, Colombia. Methods and findings: We conducted a cross-sectional study to identify individuals with early syphilis (ES) in Cali, Colombia through a city-wide network of public health centers, private sector HIV clinics and laboratory databases from public health institutions. Whole blood (WB), skin biopsies (SB), and genital and oral lesion swabs were obtained for measurement of treponemal burdens by polA quantitative polymerase chain reaction (qPCR) and for whole-genome sequencing (WGS). Among 1,966 individuals screened, 128 participants met enrollment criteria: 112 (87%) with secondary (SS), 15 (12%) with primary (PS) and one with early latent syphilis; 66/128 (52%) self-reported as heterosexual, while 48 (38%) were men who have sex with men (MSM). Genital ulcer swabs had the highest polA copy numbers (67 copies/μl) by qPCR with a positivity rate (PR) of 73%, while SS lesions had 42 polA copies/μl with PR of 62%. WB polA positivity was more frequent in SS than PS (42% vs 7%, respectively; p = 0.009). Isolation of TPA from WB by rabbit infectivity testing (RIT) was achieved in 5 (56%) of 9 ES WB samples tested. WGS from 33 Cali patient samples, along with 10 other genomic sequences from South America (9 from Peru, 1 from Argentina) used as comparators, confirmed that SS14 was the predominant clade, and that half of all samples had mutations associated with macrolide (i.e., azithromycin) resistance. Variability in the outer membrane protein (OMP) and vaccine candidate BamA (TP0326) was mapped onto the protein's predicted structure from AlphaFold. Despite the presence of mutations in several extracellular loops (ECLs), ECL4, an immunodominant loop and proven opsonic target, was highly conserved in this group of Colombian and South American TPA isolates. Conclusions: This study offers new insights into the sociodemographic and clinical features of venereal syphilis in a highly endemic area of Colombia and illustrates how genomic sequencing of regionally prevalent TPA strains can inform vaccine development. [ABSTRACT FROM AUTHOR]

The damage and effects of fire on the native vegetation of Central Chile have been increasing in recent years due to drought conditions and the state of abandonment of the Mediterranean forests. The objective of this research was to study the damage and effects of fire in four regions of Central Chile, in order to establish adequate post-fire restoration proposals. The method consisted of the analysis of eight data sampling areas on native plant species affected by fire and sectors for statistical comparison (not burned). Consequently, it was possible to establish physical restoration measures and recovery proposals based on planting native species of the place affected by the fire. In conclusion, it can be indicated that Mediterranean landscapes need measures to accelerate the process of ecological restoration, due to the scarce recovery of vegetation due to the increase in the recurrence and intensity of forest fires. [ABSTRACT FROM AUTHOR]

Cycling is a desirable mode of transportation in urban areas due to its environmental, social, and economic benefits. Design manuals are used as standardized references and guides to provide safe, functional, and convenient bicycle infrastructure. These guidelines usually provide best practice recommendations and refer to minimum requirements for dimensions (geometry) and materials. However, these documents rarely include input from cyclists. Unlike the infrastructure service perceived by motorists, which is related to performance measurements such as speed or travel time, the quality of service (QoS) experienced by pedestrians and cyclists is strongly influenced by perceptions (e.g., safety) owing to the fact that they are directly exposed to the environment. Beyond the performance-related indicators (e.g., Level of Service), when cyclists assess QoS, their cognitive process incorporates their perceptions of the surroundings. We present a user-oriented perspective in this paper, since supply-oriented evaluation and design has been carried out for decades without giving a relevant role to user perceptions. Our objective is to uncover factors explaining QoS perceived by cyclists from users' perceptions and to analyze new contributions to existing bicycle infrastructure design practices. By means of stepwise models from cyclist perception intercept surveys in Bogotá, Colombia, we uncovered factors that explain QoS. Model testing and site visits enrich the analysis of the six statistically significant variables that explain QoS. This research raises an interesting discussion on the general approach and philosophy of the bicycle infrastructure design guidelines and evidences that cyclists' perceptions have substantial potential for future research and application. [ABSTRACT FROM AUTHOR]

Brain arteriovenous malformations (bAVM) are complex vascular diseases. Several models have been used to simulate endovascular treatments; thus in vitro models have not been widely employed because it has been difficult to recreate realistic phantoms of this disease.To describe the development and evaluate the preliminary experience of a novel bAVM in vitro model for endovascular embolization using millifluidic three-dimensional (3D) printing technology.We designed a bAVM phantom starting from simple to more complex designs, composed of a nidus, feeding arteries and draining vein. We recreate the design by using millifluidic technology with stereolithography 3D printing. Structural and functional tests were performed using angiographic images and computer flow dynamics. Treatment simulations with ethylene vinyl alcohol were tested using two different microcatheter position techniques. A Likert-scale questionnaire was applied to perform a qualitative evaluation of the model.We developed a realistic model of a bAVM with hollow channels. The structural evaluation showed a high precision of the 3D printing process. Embolization tests with the liquid agent gave similar sensations and material behaviour as in vivo cases. There were no significant differences between microcatheter position techniques, thus we observed a trend for better nidus filling with a deeper in-nidus position technique.We were able to create and test a novel bAVM in vitro model with stereolithography 3D printing in resin. It showed a high capacity for simulating endovascular embolization characteristics, with an excellent user experience. It could be potentially used for training and testing of bAVM embolizations. [ABSTRACT FROM AUTHOR]