134 research outputs found
The backbone of PAGES 2k: data management and archiving
No full textProgram NewsLucien von Gunten, D.M. Anderson, B. Chase, M. Curran, J. Gergis, E.P. Gille, W. Gross, S. Hanhijärvi, D. S. Kaufman, T. Kiefer, N.P. McKay, I. Mundo, R. Neukom, M. Sano, A. Shah, J. Tyler, A. Viau, S. Wagner, E.R. Whal and D. Willar
Active pixel sensor array for high spatio-temporal resolution electrophysiological recordings from single cell to large scale neuronal networks
No full textThis paper presents a chip-based electrophysiological platform enabling the study of micro- and macro-circuitry in in-vitro neuronal preparations. The approach is based on a 64x64 microelectrode array device providing extracellular electrophysiological activity recordings with high spatial (21 microm of electrode separation) and temporal resolution (from 0.13 ms for 4096 microelectrodes down to 8 micros for 64 microelectrodes). Applied to in-vitro neuronal preparations, we show how this approach enables neuronal signals to be acquired for investigating neuronal activity from single cells and microcircuits to large scale neuronal networks. The main elements of the platform are the metallic microelectrode array (MEA) implemented in Complementary Metal Oxide Semiconductor (CMOS) technology similar to a light imager, the in-pixel integrated low-noise amplifiers (11 microVrms) and the high-speed random addressing logic. The chip is combined with a real-time acquisition system providing the capability to record at 7.8 kHz/electrode the whole array and to process the acquired signals
Large-Scale, High resolution data acquisition system for extracellular recording of electrophysiological activity
No full textNeukom, Darby (Death, 1889-03-12)
No full textAddress: Laffayette St.Age at death: 10235/Pg. 28/1889/M W S/City/Dr. R.L. Thomas/P. Gilligan/St. Joseph NewOriginal record filed in drawer labeled 'Nehm-Nia'
Inconsistent comparison of temperature reconstructions over the Common Era
No full textBüntgen et al. (2020) present a new reconstruction of extra-tropical summer temperatures based on updated versions of a large number of summer temperature sensitive tree-ring width chronologies from the Northern Hemisphere (NH), which cover the full Common Era (CE). This new dataset allows the authors to draw conclusions about NH temperature history and its relation to climate forcing, marking an important contribution to our understanding of past climate changes. While we have no issues with the main conclusions of B20, here we show that their comparison with PAGES 2k reconstructions is flawed: B20′s reconstruction focused on regional, summertime temperature, while the PAGES 2k reconstruction targeted global, annual mean temperature. For their reconstruction intercomparisons, B20 rescale all six tree-ring based reconstructions to their regional observational target but fail to do this same processing step with the PAGES 2k reconstructions. This inconsistent comparison leads B20 to incorrectly conclude that the PAGES 2k reconstructions severely lack variance and are therefore unreliable. In this contribution, we present a consistent comparison of the B20 and PAGES 2k reconstructions, and we highlight the importance of careful illustrations for interpreting scientific results both in the literature and in the public discussion. Our results show that, if more accurate methods for comparisons are applied, the temperature history and low-frequency amplitudes of the different proxy selection approaches and reconstruction products are not at odds, but actually consistent with the differences between their targets over the pre-industrial CE
Near infrared image sensor with integrated germanium photodiodes
No full textNear infrared image sensor with integrated germanium photodiode
Data assimilation-based surface temperature reconstructions over the last two millennia over Antarctica
No full textThis dataset contains data assimilation-based temperature and δ18O reconstructions in 10 Antarctic regions over the last two millennia, presented in :
Klein, F., Abram, N. J., Curran, M. A. J., Goosse, H., Goursaud, S., Masson-Delmotte, V., Moy, A., Neukom, R., Orsi, A., Sjolte, J., Steiger, N., Stenni, B., and Werner, M.: Assessing the robustness of Antarctic temperature reconstructions over the past two millennia using pseudoproxy and data assimilation experiments, Clim. Past Discuss., https://doi.org/10.5194/cp-2018-90, in review, 2018.
We use a new database of stable oxygen isotopes in ice cores compiled in the framework of Antarctica2k (Stenni et al., 2017) to constrain model ensembles derived from two simulations: one performed using ECHAM5-MPI-OM that covers the period 800-1999 CE with a horizontal resolution of 3.75° by 3.75° (Sjolte et al., 2018), and the other performed with ECHAM5-wiso, spanning 1871-2011 CE at 1.125° spatial resolution (Steiger et al., 2017). This latter simulation is available here.
Four netCDF files are available:
d18O_DA_ECHAM5-MPI-OM_1-2015.nc: data assimilation-based δ18O reconstructions using the model ensemble derived from ECHAM5-MPI-OM
ts_DA_ECHAM5-MPI-OM_1-2015.nc: data assimilation-based surface temperature reconstructions using the model ensemble derived from ECHAM5-MPI-OM
d18O_DA_ECHAM5-wiso_1-2015.nc: data assimilation-based δ18O reconstructions using the model ensemble derived from ECHAM5-wiso
ts_DA_ECHAM5-wiso_1-2015.nc: data assimilation-based surface temperature reconstructions using the model ensemble derived from ECHAM5-wiso
The variables included in the NetCDF files are:
region: integers from 1 to 10 corresponding to the ID of the ten reconstructions targets, that were defined in Stenni et al. (2017):
1: East Antarctic Plateau
2: Wilkes Land Coast
3: Weddell Sea Coast
4: Antarctic Peninsula
5: West Antarctic Ice Sheet
6: Victoria Land Coast-Ross Sea
7: Dronning Maud Land Coast
8: West Antarctica
9: East Antarctica
10: Antarctica
time: integers from 1 to 2015, corresponding to the years CE covered by the reconstructions
DA_ts (or DA_d18O): data assimilation-based reconstructed surface temperature (or δ18O). The values are annual means and are given in anomalies computed over full period. The units are degrees celsius (or permil).
DA_ts_std (or DA_d18O_std): Weighted standard deviation of the particles used for reconstructing temperature (or δ18O). The units are degrees celsius (or permil).
For a detailed description of the experimental design, please see the associated publication (Klein et al., 2018). Don't hesitate to contact François Klein for more information.
References
Klein, F., Abram, N. J., Curran, M. A. J., Goosse, H., Goursaud, S., Masson-Delmotte, V., Moy, A., Neukom, R., Orsi, A., Sjolte, J., Steiger, N., Stenni, B., and Werner, M.: Assessing the robustness of Antarctic temperature reconstructions over the past two millennia using pseudoproxy and data assimilation experiments, Clim. Past Discuss., https://doi.org/10.5194/cp-2018-90, in review, 2018.
Sjolte, J., Sturm, C., Adolphi, F., Vinther, B. M., Werner, M., Lohmann, G., and Muscheler, R.: Solar and volcanic forcing of North Atlantic climate inferred from a process-based reconstruction, Climate of the Past, 14, 1179–1194, https://doi.org/10.5194/cp-14-1179-2018, 2018.
Steiger, N. J., Steig, E. J., Dee, S. G., Roe, G. H., and Hakim, G. J.: Climate reconstruction using data assimilation of water isotope ratios from ice cores, Journal of Geophysical Research: Atmospheres, 122, 1545–1568, https://doi.org/10.1002/2016JD026011, 2017.
Stenni, B., Curran, M. A. J., Abram, N. J., Orsi, A., Goursaud, S., Masson-Delmotte, V., Neukom, R., Goosse, H., Divine, D., van Ommen, T., Steig, E. J., Dixon, D. A., Thomas, E. R., Bertler, N. A. N., Isaksson, E., Ekaykin, A., Werner, M., and Frezzotti, M.: Antarctic climate variability on regional and continental scales over the last 2000 years, Climate of the Past, 13, 1609–1634, https://doi.org/10.5194/cp-13-1609-2017, 2017.</p
Povijest medicine vinodolskog kraja u drugoj polovici 19. i početkom 20. stoljeća
No full textMedicina u 19. stoljeće ulazi s bogatom
baštinom iz prethodnoga stoljeća. U 18.
stoljeću došlo se do mnogih medicinskih
otkrića, počelo se rješavati javnozdravstvene probleme, stvaraju se znanstvena
i stručna djela, ali i popularna literatura
s brojnim javnozdravstvenim temama
namijenjenima neukom puku. Tijekom 19.
stoljeća medicina se koristi svim rezultatima napretka tehnike i prirodnih znanosti
i na nju se izravno nastavlja medicina 20.
stoljeća. Brojne pretpostavke i teorijska
razmatranja liječnika iz 19. stoljeća potvrdila su se u 20. stoljeću, kada se došlo i
do mnogih novih otkrića, koja se dotad
nisu ni naslućivala
Essays on Cooperation and Coordination
No full textThis thesis examines questions related to game theory, and in particular cooperation and coordination among economic agents.
In the first chapter (joint with Noah Myung) we propose a decision making process meant to mimic human behavior. This process is implemented with computational agents. We use these computational agents to run simulations of two coordination games, the minimum-effort coordination game and the Battle of the Sexes game. We find that the computational agents exhibit behavior similar to human subjects from previous experimental work. We then use the computational testbed to develop experimental hypotheses, which are then confirmed in the laboratory using human subjects. In particular, we show that higher cost may actually lead to higher average payoffs in the minimum-effort coordination game.
The second chapter examines a model of infinitely repeated games in which agents are boundedly rational. I show that the number of equilibrium outcomes is smaller when agents are boundedly rational. Importantly, cooperative outcomes are still possible in equilibrium, even when players cannot use sophisticated strategies and are not able to perfectly monitor their opponents. The strategy that leads to cooperation is called "Win-Stay, Lose-Shift". Using this strategy, I show that cooperation is possible in equilibrium for a large class of 2x2 games. I also give necessary and sufficient conditions on equilibrium structure for Nx2 games. These conditions suggest that in equilibrium, players must be able to cooperate without getting caught in long periods of conflict.
The final chapter focuses on a class of minimum-effort coordination games. I show that the symmetric quantal response equilibrium correspondence takes the shape of an s-shaped curve as long as players are sufficiently rational. Under certain assumptions, this s-shaped correspondence leads to hysteresis. Based on these theoretical results, I develop experiments with the minimum-effort coordination game, and test the hysteresis hypothesis in the laboratory. I find evidence that this hysteresis does occur when human subjects play the minimum-effort coordination game in the lab.</p
- …
