Search results for "Models"
showing 10 items of 8211 documents
L’historien et ses modèles
2010
Parler des modèles en histoire est une affaire délicate, car le mot recouvre des pratiques historiennes différentes depuis son apparition dans la discipline, après la dernière guerre mondiale. Pour une minorité d’historiens surtout spécialisés en histoire économique, il correspond à une vision nouvelle de la discipline qui tenterait d’intégrer certaines démarches mathématiques, en particulier aujourd’hui la théorie des jeux. Pour d’autres, en revanche, parler de modèles relèverait surtout d’une évolution du vocabulaire, sans impliquer de véritable mutation disciplinaire. Les historiens construisent et utilisent surtout des modèles explicatifs, voire palliatifs quand ils ont de trop grandes …
Reservoir computing model of prefrontal cortex creates novel combinations of previous navigation sequences from hippocampal place-cell replay with sp…
2019
As rats learn to search for multiple sources of food or water in a complex environment, they generate increasingly efficient trajectories between reward sites. Such spatial navigation capacity involves the replay of hippocampal place-cells during awake states, generating small sequences of spatially related place-cell activity that we call “snippets”. These snippets occur primarily during sharp-wave-ripples (SWRs). Here we focus on the role of such replay events, as the animal is learning a traveling salesperson task (TSP) across multiple trials. We hypothesize that snippet replay generates synthetic data that can substantially expand and restructure the experience available and make learni…
Do social comparison and coping styles play a role in the development of burnout? Cross-sectional and longitudinal findings
2006
The present longitudinal research among 558 teachers focused on the role of upward comparisons (with others performing better), downward comparisons (with others performing worse), and coping styles in relation to burnout. Assessed were identification (recognizing oneself in the other) and contrast (seeing the other as a competitor) in upward and downward comparison. Cross-sectionally, downward identification and upward contrast were positively related to burnout and negatively related to a direct coping style, whereas upward identification was negatively related to burnout and positively related to a direct coping style. Downward identification was positively related to a palliative coping…
Economics of climate change : sensitivity analysis of social cost of carbon
2016
Social cost of carbon (SCC) is the key concept in the economics of climate change. It measures the economic cost of climate impacts. SCC has influence on how beneficial it is to prevent climate change: if the value of SCC increases, investments to low-carbon technology become more attractive and profitable. This paper examines the sensitivity of two important assumptions that affect to SCC: the choice of a discount rate and time horizon. Using the integrated assessment model, we calculate SCC estimates with multiple discount rates and various time horizon lengths. Our results show that discount rate and time horizon have great effect on SCC. For example, the SCC estimates are drastically re…
Effectiveness of a new method of disinfecting the root canal, using Er, Cr:YSGG laser to kill Enterococcus faecalis in an infected tooth model.
2013
Some lasers have demonstrated to provide effective disinfection when used as adjunctive device to the conventional treatment. The aim of this in vitro study was to determine the effectiveness of the erbium, chromium:yttrium scandium gallium garnet (Er, Cr:YSGG) laser by measuring its bactericidal effect inside the root canal experimentally colonized with Enterococcus faecalis. The laser was tested at different irradiation times (30 and 60 s) and energy of impulses (75 and 25 mJ). A total of 52 single-rooted extracted human teeth were endodontically prepared with rotary instrumentation. All were sterilized and inoculated with a suspension of E. faecalis (105 bacteria/ml). The teeth were rand…
A halocin acting on Na+/H+ exchanger of Haloarchaea as a new type of inhibitor in NHE of mammals
2006
10 páginas, 3 figuras.
Flow cytometric kinetic assay of the activity of Na+/H+ antiporter in mammalian cells.
2004
Background The Na+/H+ exchanger (NHE) of mammalian cells is an integral membrane protein that extrudes H+ ion in exchange for extracellular Na+ and plays a crucial role in the regulation of intracellular pH (pHi). Thus, when pHi is lowered, NHE extrudes protons at a rate depending of pHi that can be expressed as pH units/s. Methods To abolish the activity of other cellular pH-restoring systems, cells were incubated in bicarbonate-free Dulbecco's modified Eagle's medium buffered with HEPES. Flow cytometry was used to determine pHi with 2′,7′-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein acetoxymethyl ester or 5-(and-6)-carboxy SNARF-1 acetoxymethyl ester acetate, and the appropriate fluo…
Towards Human-Bot Collaborative Software Architecting with ChatGPT
2023
Architecting software-intensive systems can be a complex process. It deals with the daunting tasks of unifying stakeholders' perspectives, designers' intellect, tool-based automation, pattern-driven reuse, and so on, to sketch a blueprint that guides software implementation and evaluation. Despite its benefits, architecture-centric software engineering (ACSE) inherits a multitude of challenges. ACSE challenges could stem from a lack of standardized processes, socio-technical limitations, and scarcity of human expertise etc. that can impede the development of existing and emergent classes of software (e.g., IoTs, blockchain, quantum systems). Software Development Bots (DevBots) trained on la…
A topology-constrained distance network algorithm for protein structure determination from NOESY data.
2005
This article formulates the multidi- mensional nuclear Overhauser effect spectroscopy (NOESY) interpretation problem using graph theory and presents a novel, bottom-up, topology-con- strained distance network analysis algorithm for NOESY cross peak interpretation using assigned resonances. AutoStructure is a software suite that implements this topology-constrained distance net- work analysis algorithm and iteratively generates structures using the three-dimensional (3D) protein structure calculation programs XPLOR/CNS or DY- ANA. The minimum input for AutoStructure in- cludes the amino acid sequence, a list of resonance assignments, and lists of 2D, 3D, and/or 4D-NOESY cross peaks. AutoStru…
MultiSlice human organ extraction based on GVF
2008
Segmentation techniques based on active contours algorithm are widely used in medical imaging. Unfortunately, they require a lot of parameters to be used and this can rep- resent an issue for those physicians with not much informatics skills. This paper proposes a software tool which allows to segment multiple slice can differ organ extraction setting a small number of parameters. Moreover, the tool offers the functionality to perform a multiple segmentation the same time, so that an entire volume composed by hundreds slices can be segmented.