452 research outputs found
Calling vs Receiving Party Pays: Market Penetration and the Importance of the Call Externality
In this paper we study how the access price affects the choice of the tariff regime taken by the network operators. We show that for high values of the access price, that is taken as a parameter by the firms, networks decide to charge only the callers. Otherwise, for low values of the access charge, networks charge also the receivers. Moreover, we compare market penetration and total welfare between the two price regimes. Our model suggests that, for high values of call externality, market penetration and total welfare are larger in Receiving Party Pays regime when the access charge is close to zero.Gender Segregation, Occupational Aspirations, Children, Socialization, Agency, Personality Traits, Mechanisms, British Household Panel Survey
Bidirectional DC-DC Converter Topologies for Low-Voltage Battery Interface: Comparative Assessment
The growing interest towards efficient and reliable bidirectional DC-DC converter topologies for interfacing low-voltage (LV) batteries, eg. 48 V, with a high-voltage (HV) DC-link, eg. 400 V, has driven the research toward the investigation of many different topologies. In this paper, three isolated and bidirectional topologies have been selected and compared to each other, where these topologies are seen as the state-of-the-art topologies for battery-fed systems. The introduced comparison includes the number of used semiconductor devices and passive elements, the rated voltage and current of the different semiconductor devices, the forecasted switching and conduction losses using PLECS, and the estimated volume and power losses of the employed magnetic elements. Furthermore, the comparison includes simulation results using PLECS considering a 1.5 kW power level
Reduction of Output Capacitance for DAB DC-DC Converters in DC Microgrids by Shaping Resistive Output Impedance
Strategic aims for improving the regulatory assessment of Developmental Neurotoxicity (DNT) using non-animal methods
Currently, the identification of chemicals that have the potential to induce developmental neurotoxicity (DNT) is based on animal testing, since there are no regulatory accepted alternative methods for this purpose. Since at the regulatory level, systematic testing of DNT is not a standard requirement within the EU legislation of chemical safety assessment, DNT testing is only performed in higher tiered tests triggered based on structure activity relationships or evidence of neurotoxicity in systemic adult studies. However, these triggers are rarely used and in addition do not always serve as reliable indicators of DNT as they are observed in an adult rodent animal. Consequently, to date only a limited amount of chemicals (Grandjean and Landrigan, 2006; Smirnova et al., 2014), mainly pesticides (Bjørling-Poulsen et al., 2008) have been tested under US EPA (OPPTS 870.630) or OECD DNT TG 426. Therefore, there is the pressing need for developing alternative methodologies that can more rapidly and cost-effectively screen large numbers of chemicals for their potential to cause DNT.
In this report we propose that in vitro studies could contribute to the identification of potential triggers for DNT evaluation since existing cellular models permit the evaluation of a chemical impact on key neurodevelopmental processes, mimicking different windows of human brain development, especially if human models derived from induced pluripotent stem cells are applied. Furthermore, the battery of currently available DNT alternative test methods anchored to critical neurodevelopmental processes and key events identified in DNT Adverse Outcome Pathways (AOPs) could be applied to generate in vitro data useful for various regulatory purposes. Incorporation of in vitro mechanistic information would increase scientific confidence in decision making, by decreasing uncertainty and leading to refinement of chemical grouping according to biological activity. In this report development of IATA (Integrated Approaches to Testing and Assessment) based on key neurodevelopmental processes and AOP-informed is proposed as a tool for not only speeding up chemical screening, but also providing mechanistic data in support of hazard assessment and in the evaluation of chemical mixtures. Such mechanistically informed IATA for DNT evaluation could be developed integrating various sources of information (e.g., non-testing methods, in vitro approaches, as well as in vivo animal and human data), contributing to screening for prioritization, hazard identification and characterization, and possibly safety assessment of chemicals, speeding up the evaluation of thousands of compounds present in industrial, agricultural and consumer products that lack safety data on DNT potential. It is planned that the data and knowledge generated from such testing will be fed into the development of an OECD guidance document on alternative approaches to DNT testing.JRC.F.3-Chemicals Safety and Alternative Method
Animal Research for Alzheimer Disease: Failures of Science and Ethics
This chapter addresses the epidemiology and current understanding of AD as a scientific and societal challenge, reviews the uses and results of animal research in basic science and drug development, and discusses risk factors and funding. Important follow-up topics, including current and in-development, human-relevant approaches for replacement of the failed animal research paradigm, deserve comparable treatment and hence are not addressed here. The reader is referred to the list of recommended readings at the end of the chapter for further discussion of these topics
The Three-Layer Concentric Model of Glioblastoma: Cancer Stem Cells, Microenvironmental Regulation, and Therapeutic Implications
Tumors arising in the central nervous system are thought to
originate from a sub-population of cells named cancer stem cells
(CSCs) or tumor initiating cells (TICs) that possess an immature
phenotype, combined with self-renewal and chemotherapy resistance
capacity. Moreover, in the last years, these cells have been
identified in particular brain tumor niches fundamental for
supporting their characteristics. In this paper, we report studies
from many authors demonstrating that hypoxia or the so called
“hypoxic niche” plays a crucial role in controlling CSC molecular
and phenotypic profile. We recently investigated the relationship
existing between Glioblastoma (GBM) stem cells and their niche,
defining the theory of three-concentric layers model for GBM mass.
According to this model, GBM stem cells reside preferentially
within the hypoxic core of the tumour mass, while more
differentiated cells are mainly localized along the peripheral and
vascularized part of the tumour. This GBM model provides
explanation of the effects mediated by the tumour microenvironment
on the phenotypic and molecular regulation of GBM stem cells,
describing their spatial distribution in the tumor bulk. Moreover,
we discuss the possible clinical implications of the creation of
this model for future GBM patient management and novel therapeutic
strategies development
Calling vs receiving party pays : market penetration and the importance of the call externality
In this paper we study how the access price affects the choice of the tariff regime taken by the network operators. We show that for high values of the access price, that is taken as a parameter by the firms, networks decide to charge only the callers. Otherwise, for low values of the access charge, networks charge also the receivers. Moreover, we compare market penetration and total welfare between the two price regimes. Our model suggests that, for high values of call externality, market penetration and total welfare are larger in Receiving Party Pays regime when the access charge is close to zero
A Survey on Monitoring Innovation and Societal Impact of EU-funded Research: Factual Summary Report
The Joint Research Centre (JRC) of the European Commission (EC), in collaboration with the EC Directorate General for Research and Innovation initiated an activity to define suitable indicators to retrospectively assess the impact of European Union (EU)-funded research. To this aim, the JRC conducted a survey addressed to current and former participants of EC-funded research projects in the fields of Alzheimer’s disease and other dementias, breast cancer, and prostate cancer.
This summary report provides a brief factual overview of the replies received, with information on the respondents as well as the number of responses and range of opinions. The replies gathered through this survey will help the European Commission assess how EU-funded research activities have contributed to innovation and impact.JRC.F.3-Chemicals Safety and Alternative Method
Molecular Mechanisms of HIF-1α Modulation Induced by Oxygen Tension and BMP2 in Glioblastoma Derived Cells
BACKGROUND: Glioblastoma multiforme (GBM) is one of most common and still poorly treated primary brain tumors. In search for new therapeutic approaches, Bone Morphogenetic Proteins (BMPs) induce astroglial commitment in GBM-derived cells in vitro. However, we recently suggested that hypoxia, which is characteristic of the brain niche where GBM reside, strongly counter-acts BMP effects. It seems apparent that a more complete understanding of the biology of GBM cells is needed, in particular considering the role played by hypoxia as a signaling pathways regulator. HIF-1alpha is controlled at the transcriptional and translational level by mTOR and, alike BMP, also mTOR pathway modulates glial differentiation in central nervous system (CNS) stem cells. METHODOLOGY/PRINCIPAL FINDINGS: Here, we investigate the role of mTOR signaling in the regulation of HIF-1alpha stability in primary GBM-derived cells maintained under hypoxia (2% oxygen). We found that GBM cells, when acutely exposed to high oxygen tension, undergo Akt/mTOR pathway activation and that BMP2 acts in an analogous way. Importantly, repression of Akt/mTOR signaling is maintained by HIF-1alpha through REDD1 upregulation. On the other hand, BMP2 counter-acts HIF-1alpha stability by modulating intracellular succinate and by controlling proline hydroxylase 2 (PHD2) protein through inhibition of FKBP38, a PHD2 protein regulator. CONCLUSIONS/SIGNIFICANCE: In this study we elucidate the molecular mechanisms by which two pro-differentiating stimuli, BMP2 and acute high oxygen exposure, control HIF-1alpha stability. We previously reported that both these stimuli, by inducing astroglial differentiation, affect GBM cells growth. We also found differences in high oxygen and BMP2 sensitivity between GBM cells and normal cells that should be further investigated to better define tumor cell biology
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