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This paper presents MATLAB user interfaces for two multiphase kinetic models: the kinetic double-layer model of aerosol surface chemistry and gas--particle interactions (K2-SURF) and the kinetic multilayer model of aerosol surface and bulk chemistry (KM-SUB). Each interface has simple and user-friendly features that allow undergraduate and graduate students in physical, environmental, and atmospheric chemistry classes to learn about multiphase chemistry modeling without prior computer programming or modeling experience. It is easy to input parameters, and the simulation results are promptly displayed in the interface; thus, these model interfaces are particularly suitable for in-classroom and homework teaching applications. The model input parameters include surface and bulk reaction rate coefficients, surface accommodation coefficient, and gas and bulk diffusivities, while model outputs include gas uptake coefficient and surface and bulk concentrations. Students can use the K2-SURF interface to simulate surface processes and the KM-SUB interface to simulate surface and bulk processes. Example simulations were performed for each interface to present atmospherically relevant applications and to demonstrate its versatility for exploring model sensitivity on various kinetic parameters. The K2-SURF interface was used to show how the rate of ozone uptake by an organic surface and temporal evolution of surface concentrations are affected by the surface accommodation coefficient, desorption lifetime, and surface reaction rate coefficient. Additionally, the KM-SUB interface was applied to demonstrate how bulk diffusivities impact the degradation kinetics of oleic acid particles, so that students can learn how the phase state (liquid vs semisolid vs glassy solid) impacts multiphase chemical kinetics. The developed K2-SURF and KM-SUB interfaces are effective tools for modeling surface and bulk reactions in college-level educational settings, helping students to obtain a deeper understanding of the complex behaviors of heterogeneous and multiphase systems.

Road traffic is a significant source of particulate matter pollution, whose exposure is a significant risk factor in pregnancy-related health outcomes. The exact mechanisms behind the relationship between traffic-related air pollution (TRAP) exposure and adverse pregnancy outcomes remain unclear. We aim to assess the relationship between exposure to brake and tire wear-associated metals and oxidative potential and ischemic placental disease (IPD). Data were assembled from a final population of 178 women who sought specialized prenatal care at UCLA between 2016 and 2019 in Los Angeles, CA. Modeled first trimester exposures to chemical constituents and oxidative stress potential of PM _2.5 , black carbon, and PM _2.5 mass concentration. Speciated measurements included tracers of brake wear (barium), tire wear (zinc), and oxidative potential markers based on metal concentrations (KM-SUB-ELF ROS) or laboratory assays (DTT loss, OH radical formation). Exposures were modeled by integrating data from filter samples, a low-cost PM _2.5 sensor network, and land-use data. We used logistic regression to estimate the associations between air pollution exposures and IPD, adjusting for covariates assessed through medical records and interviews. Scaled to the interquartile range, odds ratios (95% CI) were as follows: barium OR: 1.7 (1.1, 2.7), zinc OR: 1.4 (.86, 2.4), and oxidative potential markers, both modeled as well as measured through DTT loss and OH formation assays (ORs ranging from 1.1-2.0). Point estimates of effect sizes for PM _2.5 and black carbon were lower than most measurements (ORs: 1.3-1.4). mass and black carbon. Our findings suggest two key points: (i) metals associated with brake and tire wear, currently unregulated, may play a role in the relationship between TRAP and adverse pregnancy outcomes, and (ii) reducing tailpipe emissions may not be sufficient to protect pregnant women from TRAP.

Abstract Objective Toxoplasma gondii is a ubiquitous parasite of medical and veterinary importance; however, there exists no cure for chronic toxoplasmosis. Metabolic enzymes required for the production and maintenance of tissue cysts represent promising targets for novel therapies. Here, we use reverse genetics to investigate the role of Toxoplasma phosphoglucomutase 1, PGM1, in Toxoplasma growth and cystogenesis. Results We found that disruption of pgm1 did not significantly affect Toxoplasma intracellular growth and the lytic cycle. pgm1-defective parasites could differentiate into bradyzoites and produced cysts containing amylopectin in vitro. However, cysts produced in the absence of pgm1 were significantly smaller than wildtype. Together, our findings suggest that PGM1 is dispensable for in vitro growth but contributes to optimal Toxoplasma cyst development in vitro, thereby necessitating further investigation into the function of this enzyme in Toxoplasma persistence in its host.

Concentration of air pollutants has generally been considered uniform in indoor environments. Here, the authors show that chlorinated cleaning products generate concentration gradients of pollutants due to photochemical reactions in sunlit areas, requiring a finer assessment of human exposure to these contaminants.

Future changes in the North American monsoon, a circulation system that brings abundant summer rains to vast areas of the North American Southwest, could have significant consequences for regional water resources. How this monsoon will change with increasing greenhouse gases, however, remains unclear, not least because coarse horizontal resolution and systematic sea-surface temperature biases limit the reliability of its numerical model simulations. Here we investigate the monsoon response to increased atmospheric carbon dioxide (CO 2) concentrations using a 50-km-resolution global climate model which features a realistic representation of the monsoon climatology and its synoptic-scale variability. It is found that the monsoon response to CO 2 doubling is sensitive to sea-surface temperature biases. When minimizing these biases, the model projects a robust reduction in monsoonal precipitation over the southwestern United States, contrasting with previous multi-model assessments. Most of this precipitation decline can be attributed to increased atmospheric stability, and hence weakened convection, caused by uniform sea-surface warming. These results suggest improved adaptation measures, particularly water resource planning, will be required to cope with projected reductions in monsoon rainfall in the American Southwest.

Toxoplasmosis is a zoonotic infection affecting approximately 30% of the world's human population. After sexual reproduction in the definitive feline host, Toxoplasma oocysts, each containing 8 sporozoites, are shed into the environment where they can go on to infect humans and other warm-blooded intermediate hosts. Here, we use an in vitro model to assess host transcriptomic changes that occur in the earliest stages of such infections. We show that infection of rat intestinal epithelial cells with mature sporozoites primarily results in higher expression of genes associated with Tumor Necrosis Factor alpha (TNFα) signaling via NF-κB. Furthermore, we find that, consistent with their biology, these mature, invaded sporozoites display a transcriptome intermediate between the previously reported day 10 oocysts and that of their tachyzoite counterparts. Thus, this study uncovers novel host and pathogen factors that may be critical for the establishment of a successful intracellular niche following sporozoite-initiated infection.

In the ongoing debate about “Studierbarkeit”, the individual study process offers a promising starting point for institutional attempts to support study success. After briefly introducing established theoretical perspectives and empirical findings on the prediction of study success, I will argue for a closer alignment of research on and practical implementations of student support. Furthermore, I will present a process model of the – most critical – first year of study and demonstrate its fit using data from three cohorts. The practical implications derived from this model, as well as some strategic recommendations for how higher education institutions can foster study success are outlined.

Pascale Guiton works in the field of parasitology at a primarily undergraduate institution. In this mSphere of Influence article, she reflects on her difficulties as a faculty of color to discuss socioscientific issues in her classrooms. T.

Invasive pneumococcal meningitis is a life-threatening infectious disease affecting the central nervous system. It continues to be the most common type of community-acquired acute bacterial meningitides. Despite advances in neuro-critical care, the case fatality rate remains high. Rapid diagnosis and initiation of antibiotic therapy precludes mortality and long-term neurological sequelae in survivors. However, not all cases are easily recognised, and unanticipated complications may impede optimal course and outcome. Here, we describe a case of invasive pneumococcal meningoencephalitis in a 65-year-old man with an unusual initial presentation and pitfalls in the course of the disease. We highlight the importance of early diagnosis and treatment as well as recognition and management of complications.

Toxoplasmosis is a zoonotic infection affecting approximately 30% of the world's human population. After sexual reproduction in the definitive feline host, Toxoplasma oocysts, each containing 8 sporozoites, are shed into the environment where they can go on to infect humans and other warm-blooded intermediate hosts. Here, we use an in vitro model to assess host transcriptomic changes that occur in the earliest stages of such infections. We show that infection of rat intestinal epithelial cells with mature sporozoites primarily results in higher expression of genes associated with Tumor Necrosis Factor alpha (TNFα) signaling via NF-κB. Furthermore, we find that, consistent with their biology, these mature, invaded sporozoites display a transcriptome intermediate between the previously reported day 10 oocysts and that of their tachyzoite counterparts. Thus, this study uncovers novel host and pathogen factors that may be critical for the establishment of a successful intracellular niche following sporozoite-initiated infection.

According to the challenge-hindrance model, challenge stressors contain both stressful and challenging aspects, hindrance stressors only stressful aspects. Typically, negative outcomes of challenge stressors refer to well-being (strain), positive outcomes to so-called work outcomes (e.g., productivity, intention to quit). As both effects occur simultaneously, the positive outcomes often emerge only when controlling for the negative effects. We suggest that the negative "and" the positive effects of challenge stressors may refer to well-being. Specifically, we propose challenge to indicate competence, thus fostering organization-based self-esteem (OBSE), which, in turn, should enhance more general indicators of positive well-being. We explored the effect of time pressure (a prototypical challenge stressor) on a general well-being variable (positive attitude towards life; PAL). We postulated challenge stressors to be associated with PAL positively via OBSE and negatively via strain. These processes should (a) result in a non-significant bivariate association, which should (b) become significant once strain is controlled (suppression), but (c) become insignificant again once OBSE is controlled (mediation). Using structural equation modeling, we could confirm our hypotheses in a cross-sectional study. Results confirm the inherently ambivalent nature of time pressure, containing both positive and negative variance. In line with our theoretical position, results suggest that the negative and the positive outcomes may be conceived in terms of different aspects of well-being, in addition to "work outcomes" that do not refer to well-being. This concept of challenge stressors may help to explain why many people do not reduce challenge stressors even when they could: Feeling good about themselves and their lives may, at least temporarily, outweigh the strain. (Contains 2 tables and 2 figures.)

ABSTRACT Though the bacterial opportunist Enterococcus faecalis causes a myriad of hospital-acquired infections (HAIs), including catheter-associated urinary tract infections (CAUTIs), little is known about the virulence mechanisms that it employs. However, the endocarditis- and biofilm-associated pilus (Ebp), a member of the sortase-assembled pilus family, was shown to play a role in a mouse model of E. faecalis ascending UTI. The Ebp pilus comprises the major EbpC shaft subunit and the EbpA and EbpB minor subunits. We investigated the biogenesis and function of Ebp pili in an experimental model of CAUTI using a panel of chromosomal pilin deletion mutants. A nonpiliated pilus knockout mutant (EbpABC− strain) was severely attenuated compared to its isogenic parent OG1RF in experimental CAUTI. In contrast, a nonpiliated ebpC deletion mutant (EbpC− strain) behaved similarly to OG1RF in vivo because it expressed EbpA and EbpB. Deletion of the minor pilin gene ebpA or ebpB perturbed pilus biogenesis and led to defects in experimental CAUTI. We discovered that the function of Ebp pili in vivo depended on a predicted metal ion-dependent adhesion site (MIDAS) motif in EbpA’s von Willebrand factor A domain, a common protein domain among the tip subunits of sortase-assembled pili. Thus, this study identified the Ebp pilus as a virulence factor in E. faecalis CAUTI and also defined the molecular basis of this function, critical knowledge for the rational development of targeted therapeutics. IMPORTANCE Catheter-associated urinary tract infections (CAUTIs), one of the most common hospital-acquired infections (HAIs), present considerable treatment challenges for physicians. Inherently resistant to several classes of antibiotics and with a propensity to acquire vancomycin resistance, enterococci are particularly worrisome etiologic agents of CAUTI. A detailed understanding of the molecular basis of Enterococcus faecalis pathogenesis in CAUTI is necessary for the development of preventative and therapeutic strategies. Our results elucidated the importance of the E. faecalis Ebp pilus and its subunits for enterococcal virulence in a mouse model of CAUTI. We further showed that the metal ion-dependent adhesion site (MIDAS) motif in EbpA is necessary for Ebp function in vivo. As this motif occurs in other sortase-assembled pili, our results have implications for the molecular basis of virulence not only in E. faecalis CAUTI but also in additional infections caused by enterococci and other Gram-positive pathogens.