Environmentally persistent free radicals induce airway hyperresponsiveness in neonatal rat lungs

Background  

Increased asthma risk/exacerbation in children and infants is associated with exposure to elevated levels of ultrafine particulate matter (PM). The presence of a newly realized class of pollutants, environmentally persistent free radicals (EPFRs), in PM from combustion sources suggests a potentially unrecognized risk factor for the development and/or exacerbation of asthma.     

A decision-oriented model to evaluate the effect of land use and agricultural management on herbicide contamination in stream water

Modelling stream water pollution by herbicides in agricultural areas is a critical issue since numerous and incompletely known processes are involved. A decision-oriented model, SACADEAU-Transf, which represents water and pesticide transfer in medium-sized catchments (10–50 km²) is presented. This model aims at evaluating the effect of land use, agricultural practice and landscape on the contamination of stream water in rural catchments. The processes are represented in an easily understandable way with a moderate amount of information, producing semi-quantitative and spatialized outputs. Modelling focuses on the first few months after herbicide application when high levels of contamination are generally observed, by considering transfer through the catchment area via surface and subsurface flow. The surface flow, based on a tree plot network representation of the catchment, is controlled by soil-surface properties and saturated conditions. The subsurface flow based on Topmodel concepts is controlled by the topography. Herbicide transfer is coupled to water transfer by taking into account the main characteristics of the chemicals. The model simulates the daily water and herbicide outflow at the outlets of the farmers' fields as well as from the catchment. Preliminary results on maize herbicide transfer are presented for an agricultural catchment with an area of 17 km² located in north-western France. The relevance of SACADEAU-Transf model is discussed in view of the qualities required for the decision-oriented models developed for improving agro-environmental management.     

Computationally Efficient Approaches to Characterize the Dynamic Response of Microstructures Under Mechanical Shock

We present computationally efficient models and approaches to simulate the response of microstructures under mechanical shock. These approaches include a Galerkin-based reduced-order model and a hybrid approach utilizing the response of structures to static loads combined with the dynamic shock spectrum of a spring-mass-damper system. To demonstrate the accuracy and efficiency of these approaches, we apply them on cantilever and clamped-clamped microbeams, and compare their predictions with analytical and finite-element (FE) results. We conclude that the hybrid approach is computationally efficient and accurate for microstructures behaving linearly in both quasi-static and dynamic loading conditions. The hybrid approach enables using simple analytical expressions that can be easily utilized by microelectromechanical system designers to judge the reliability of their devices. We show that reduced-order models are capable of capturing accurately the dynamic behavior of microstructures under shock pulses of various amplitudes (low-g and high-g), damping conditions, structural boundaries, and can capture linear and nonlinear behavior. Our results indicate that modeling the shock force as a quasi-static force for microstructures with low-natural frequencies may lead to erroneous results. High-g loading cases are investigated. Significant increase in the computational cost of simulations is reported when using traditional FE models because of the activation of higher order modes. The developed reduced-order model employing at least six modes is shown to be efficient in such cases. Design parameters are investigated to determine their effect on the shock resistance of microstructures. It is concluded that increasing air damping and tensile residual stresses improves the shock resistance of microstructures. A case study for the response of an optical fiber switch to shock is presented.     

Improving project forecast accuracy by integrating earned value management with exponential smoothing and reference class forecasting

In this paper, the earned value management (EVM) project control methodology is integrated with the exponential smoothing forecasting approach. This results in an extension of the known EVM and earned schedule (ES) cost and time forecasting formulas. A clear correspondence between the established approaches and the newly introduced method – called the XSM – is identified, which could facilitate future implementation. More specifically, only one smoothing parameter is needed to calculate the enhanced EVM performance factor. Moreover, this parameter can be dynamically adjusted during project progress based on information of past performance and/or anticipated management actions. Additionally, the reference class forecasting (RCF) technique can be incorporated into the XSM. Results from 23 real-life projects show that, for both time and cost forecasting, the XSM exhibits a considerable overall performance improvement with respect to the most accurate project forecasting methods identified by previous research, especially when incorporating the RCF concept.     

Epigenetic Regulation of Pulmonary Arterial Hypertension-Induced Vascular and Right Ventricular Remodeling: New Opportunities?

Pulmonary artery hypertension (PAH) is a rare chronic disease with high impact on patients’ quality of life and currently no available cure. PAH is characterized by constant remodeling of the pulmonary artery by increased proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs), fibroblasts (FBs) and endothelial cells (ECs). This remodeling eventually leads to increased pressure in the right ventricle (RV) and subsequent right ventricle hypertrophy (RVH) which, when left untreated, progresses into right ventricle failure (RVF). PAH can not only originate from heritable mutations, but also develop as a consequence of congenital heart disease, exposure to drugs or toxins, HIV, connective tissue disease or be idiopathic. While much attention was drawn into investigating and developing therapies related to the most well understood signaling pathways in PAH, in the last decade, a shift towards understanding the epigenetic mechanisms driving the disease occurred. In this review, we reflect on the different epigenetic regulatory factors that are associated with the pathology of RV remodeling, and on their relevance towards a better understanding of the disease and subsequently, the development of new and more efficient therapeutic strategies.     

Modelling denitrification at the catchment scale

The objective of this work was to evaluate the importance of heterotrophic denitrification in the fate of nitrogen surpluses at the catchment scale. For that purpose we modified the denitrification module of TNT2 model and calibrated the model on a small catchment where denitrification measurements had been performed in different locations. The main interest of the TNT2 model is its ability to simulate the dynamics of the zones where soil and shallow water table interact, making it possible to spatialize the denitrification process. Daily water and nitrogen flux at the outlet were relatively well simulated (Nash of 0.85 and 0.77). In average, the model correctly simulates the denitrification measurements (R = 0.68). Nitrogen flux towards the atmosphere, at the catchment scale (4.70 g N m^− 2 year^− 1), is of the same order of magnitude as the soluble N flux in the stream. The model was able to reproduce the distribution of denitrification in the riparian (mean of 9.26 g N m^− 2 year^− 1) and hillslope (mean of 3.45 g N m^− 2 year^− 1) domains of the catchment. The results confirm the importance of riparian denitrification, but show also that hillslope soils contribute significantly (60%) to the whole catchment denitrification. The variations of denitrification rates, and also of nitrate concentrations in stream were not very well simulated by the model, highlighting the complexity of the spatial and temporal controls of nitrogen dynamics in areas with high inputs of nitrogen fertilizers, especially under organic forms.     

Effects of Media Ratings on Children and Adolescents: A Litmus Test of the Forbidden Fruit Effect

Media ratings serve to inform parents about and protect minors from violent or otherwise harmful media content. Most of these systems use age pictograms and content warning pictograms for entertainment products. An experiment was conducted to investigate whether these pictograms, contrary to their purpose, have an appealing effect on children and adolescents. Compared to prior studies into this “forbidden fruit effect” concerning DVDs and games, more realistic materials were used. In the experiment, 322 elementary school students (9–11 years) and 335 high school students (13–15 years) were exposed to 10 DVD or game covers and asked to judge the products' attractiveness. The results show that the pictograms did not increase the attractiveness of games and DVDs for children and adolescents.     

Humanism in Contemporary Architecture: Tough- and Tender-Minded

This article situates the work of Leon Krier within the contexts of postindustrialism and postmodernism. The author is critical of Krier, and finds problematic his self-proclaimed stance of idealism/purism, a position which devalues a possible practice of direct cultural and political action, and reduces his work to the level of hollow scenography. Dutton argues that, especially in these times, architects must strive to overcome their marginalization. He points to an instrumental role for architecture in promoting transformative cultural directions, politics, and ways of life. He argues that there is maneuverability to resist dominant culture, a precondition of which is for architects to link with struggling cultures to help produce their vision and spatiality.     

Osteosarcoma of the mandible

We describe a case of osteosarcoma of the mandible presenting as a soft tissue mass associated with an enlargement of the mandibular canal at imaging work-up. Radiographic, isotopic, CT and MR features are reported.     

Nonstationary Poisson modeling of web browsing session arrivals

In this paper we show that daily web session arrivals are nonstationary Poissonian with a rate surprisingly stable, i.e., changing only once per 24 hours in all the examined cases.