649 research outputs found
Development of boron calibration via hybrid comparator method in prompt gamma activation analysis
The prompt gamma activation analysis (PGAA) facility at the Nuclear Engineering Teaching Laboratory at The University of Texas at Austin was utilized to quantify boron concentrations in boron carbide semiconductor films deposited on silicon substrates. Calibration was complicated by the unique and varying sample geometries analyzed. In addition, there was a dearth of solid materials available with quantified boron concentrations having comparable or readily modifiable dimensions to exploit for calibration purposes. Therefore, a novel hybrid comparator method was developed for the quantification of boron utilizing aluminum as an inexpensive and easily machinable reference material. Aluminum samples were manufactured with high tolerances to match the geometry of each sample of interest. Each boron carbide film sample and its congruent aluminum sample were measured in the PGAA system. The measured aluminum responses and relevant nuclear parameters were used to standardize the measurements. A boron standard was created using a procedure derived from a similar approach used by the National Institute of Standards and Technology. Quality control measurements using this standard show that the method provided accuracy to within 5% for boron quantification
Signal-Jamming in a Sequential Auction
In a recurring auction early bids may reveal biddersâ types, which in turn affects bidding in later auctions. Bidders take this into account and may bid in a way that conceals their private information until the last auction is played. The present paper analyzes the equilibrium of a sequence of ?rst-price auctions assuming bidders have stable private values. We show that signal-jamming occurs and explore the dynamics of equilibrium prices
Un progetto per Nowa Huta
Il volume raccoglie i progetti presentati alla IX Biennale Internazionale di Cracovia, 2002, sul tema "Less ideology - more geometry in the space to live the city". Oggetto del concorso sono quegli spazi della cittĂ , costruita come cittĂ dormitorio durante gli anni del Realismo Socialista, che possono diventare spazi pubblici per la cittĂ contemporanea.
Progetto vincitore del primo premio.
Born from a political will (socialist realism), from a model of urban and territorial organization (a new way of life) that imprinted its processes of conception and construction, Nowa Huta is, like all foundation towns, a city without a past, a city that appears today fixed in the everlasting present of the time (the ideology) which conceived and built it, and projected towards a future balanced between failure of the ideals (which were the very reason for the existance of the city) and the shutting-down of the huge factories to which it was connected (its practical reason). A city without a past and with an uncertain future.
But the shape of Nowa Huta, its spatial structure, has an immense debt to the history and the tradition of the architecture and, set free form its political and ideological charge, it represents today an important contribution to urban research, both on a territorial scale (location, means of transport, water supply, production settlements) and on a urban scale (quarters, residential units, public services, collective buildings, green areas, traffic in its different forms).
Therefore our reflection starts from the actual reality of the city, from its built structure (the layout of streets and its relationship with architecture, the residential districts and the emerging monuments) which represents the more constant and convincing element: the aggregative systems, the building types and the architectural forms have changed in the course of time, but the plan remained unchanged in its geometrical clearness
Fingolimod modulates dendritic architecture in a BDNF-dependent manner
The brain-derived neurotrophic factor (BDNF) plays crucial roles in both the developing and mature brain. Moreover, alterations in BDNF levels are correlated with the cognitive impairment observed in several neurological diseases. Among the different therapeutic strategies developed to improve endogenous BDNF levels is the administration of the BDNF-inducing drug Fingolimod, an agonist of the sphingosine-1-phosphate receptor. Fingolimod treatment was shown to rescue diverse symptoms associated with several neurological conditions (i.e., Alzheimer disease, Rett syndrome). However, the cellular mechanisms through which Fingolimod mediates its BDNF-dependent therapeutic effects remain unclear. We show that Fingolimod regulates the dendritic architecture, dendritic spine density and morphology of healthy mature primary hippocampal neurons. Moreover, the application of Fingolimod upregulates the expression of activity-related proteins c-Fos and pERK1/2 in these cells. Importantly, we show that BDNF release is required for these actions of Fingolimod. As alterations in neuronal structure underlie cognitive impairment, we tested whether Fingolimod application might prevent the abnormalities in neuronal structure typical of two neurodevelopmental disorders, namely Rett syndrome and Cdk5 deficiency disorder. We found a significant rescue in the neurite architecture of developing cortical neurons from Mecp2 and Cdkl5 mutant mice. Our study provides insights into understanding the BDNF-dependent therapeutic actions of Fingolimod
Immobilization of the Erupting Molar in the Syrian Hamster
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67148/2/10.1177_00220345650440061901.pd
Implantable Sensor System for Remote Detection of a Restenosis Condition
Part 7: Perceptional SystemsInternational audienceThe increase of life expectancy in the European Union, and the high risk of cardiovascular diseases associated with age, are some of the main factors to contribute to the rise of healthcare costs. An intelligent stent (e-stent), capable of obtaining and transmitting real-time measurements of physiological parameters for its clinical consultation, can be a useful tool for long-term monitoring, diagnostic, and early warning system for arterial blockage without patient hospitalization. In this paper, a behavioural model of capacitive Micro-Electro-Mechanical (MEMS) pressure sensor is proposed and simulated under several restenosis conditions. Special attention has been given to the need of an accurate fault model, obtained from realistic finite-element simulations,to ensure long-term reliability; particularly for those faults whose behavior cannot be easily described by an analytical model
Lack of Methyl-CpG Binding Protein 2 (MeCP2) Affects Cell Fate Refinement During Embryonic Cortical Development
During differentiation, neurons progressively restrict their fate repressing the expression of specific genes. Here we describe the involvement in such developmental steps of the methyl-CpG binding protein 2 (MeCP2), an epigenetic factor that participates to chromatin folding and transcriptional regulation. We previously reported that, due to transcriptional impairments, the maturation of Mecp2 null neurons is delayed. To evaluate whether this could stem from altered progenitors proliferation and differentiation, we investigated whether lack of Mecp2 affects these features both in vitro and in vivo. We show that in Mecp2 null embryonic cortexes the expression of genes defining the identity of proliferating neuroprogenitors is enriched and that their permanence in the G1 phase is prolonged. Moreover, the number of cells transitioning from a stage of maturation to a more mature one is increased in Mecp2 null embryonic cortices, in line with the central role of G1 for cell identity refinement. We thus suggest that, possibly due to the lack of proper transcriptional control normally exerted by Mecp2, fate refinement is impaired in developing null cells. We propose that the maturation delay affecting the developing Mecp2 null cortex originates, at least in part, from deranged mechanisms of cell fate refinement
Un progetto per Nowa Huta
Il volume raccoglie i progetti presentati alla IX Biennale Internazionale di Cracovia, 2002, sul tema "Less ideology - more geometry in the space to live the city". Oggetto del concorso sono quegli spazi della cittĂ , costruita come cittĂ dormitorio durante gli anni del Realismo Socialista, che possono diventare spazi pubblici per la cittĂ contemporanea. Progetto vincitore del primo premio. Born from a political will (socialist realism), from a model of urban and territorial organization (a new way of life) that imprinted its processes of conception and construction, Nowa Huta is, like all foundation towns, a city without a past, a city that appears today fixed in the everlasting present of the time (the ideology) which conceived and built it, and projected towards a future balanced between failure of the ideals (which were the very reason for the existance of the city) and the shutting-down of the huge factories to which it was connected (its practical reason). A city without a past and with an uncertain future. But the shape of Nowa Huta, its spatial structure, has an immense debt to the history and the tradition of the architecture and, set free form its political and ideological charge, it represents today an important contribution to urban research, both on a territorial scale (location, means of transport, water supply, production settlements) and on a urban scale (quarters, residential units, public services, collective buildings, green areas, traffic in its different forms). Therefore our reflection starts from the actual reality of the city, from its built structure (the layout of streets and its relationship with architecture, the residential districts and the emerging monuments) which represents the more constant and convincing element: the aggregative systems, the building types and the architectural forms have changed in the course of time, but the plan remained unchanged in its geometrical clearnes
Anti-CRISPR Phages Cooperate to Overcome CRISPR-Cas Immunity
This is the final version of the article. Available from Elsevier via the DOI in this record.Some phages encode anti-CRISPR (acr) genes, which antagonize bacterial CRISPR-Cas immune systems by binding components of its machinery, but it is less clear how deployment of these acr genes impacts phage replication and epidemiology. Here, we demonstrate that bacteria with CRISPR-Cas resistance are still partially immune to Acr-encoding phage. As a consequence, Acr-phages often need to cooperate in order to overcome CRISPR resistance, with a first phage blocking the host CRISPR-Cas immune system to allow a second Acr-phage to successfully replicate. This cooperation leads to epidemiological tipping points in which the initial density of Acr-phage tips the balance from phage extinction to a phage epidemic. Furthermore, both higher levels of CRISPR-Cas immunity and weaker Acr activities shift the tipping points toward higher initial phage densities. Collectively, these data help elucidate how interactions between phage-encoded immune suppressors and the CRISPR systems they target shape bacteria-phage population dynamics.M.L. was supported by funding from the Wellcome Trust (https://wellcome.ac.uk) (109776/Z/15/Z), which was awarded to E.R.W. E.R.W. further acknowledges the Natural Environment Research Council (https://nerc.ukri.org) (NE/M018350/1), the BBSRC (BB/N017412/1), and the European Research Council (https://erc.europa.eu) (ERC-STG-2016-714478 - EVOIMMECH) for funding. S.v.H. acknowledges funding from the People Programme (Marie Curie Actions; https://ec.europa.eu/research/mariecurieactions/) of the European Unionâs Horizon 2020 (REA grant agreement no. 660039) and from the BBSRC (BB/R010781/1). S.G. acknowledges funding (Visiting Professorship) from the Leverhulme Trust. A.B. acknowledges funding from the Royal Society. The authors thank Olivier Fradet for experimental contributions and Adair Borges and Joe Bondy-Denomy (UCSF) for providing DMS3mvir-AcrIF4 and phage JBD26
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