1,150 research outputs found
CARMA-F (CARibbean MAngroves, compilation of fossil pollen records from the Late Cretaceous to the Pliocene)
No full text[Related Links]
Article
https://www.mdpi.com/2223-7747/12/22/3852
compiles this dataset
Article
https://www.sciencedirect.com/science/article/pii/S0012825222001544
is derived from this dataset
Article
https://www.sciencedirect.com/science/article/abs/pii/S1433831923000173
is derived from this dataset
Article
https://www.sciencedirect.com/science/article/abs/pii/S0048969723024725
is derived from this dataset
Article
https://www.mdpi.com/2223-7747/12/2/244
is derived from this dataset
Article
https://www.sciencedirect.com/science/article/pii/S0277379122005510
is derived from this datasetCARMA-F (CARibbean MAngroves-Fossil) is a dataset that gathers the published fossil pollen records of mangrove taxa from the Caribbean region. The latest update includes nearly 90 localities ranging from the Late Cretaceous to the Pliocene. This dataset has been compiled to facilitate the study of the origin, evolution and diversification of Caribbean mangroves, along with the main environmental drivers involved. The data contained in CARMA-F have been used in a collection of papers by the author organized chronologically that discuss the Eocene origin, the Eocene/Oligocene evolutionary turnover and the Neogene diversification of these iconic tropical/subtropical coastal ecosystems, as occurred in the Neotropical Caribbean region. CARMA-F is provided as a spreadsheet and is open to modifications to adapt it to the particular interests of each researcher. A detailed description of the dataset in available at https://www.mdpi.com/2223-7747/12/22/3852. The dataset remains open to further updates, as new data are published/retrieved.Peer reviewe
Nonlinear dynamics for estimating the tip radius in atomic force microscopy
No full textThe accuracy of measurements in Amplitude Modulation Atomic Force Microscopy (AFM) is directly related to the geometry of the tip. The AFM tip is characterized by its radius of curvature, which could suffer from alterations due to repetitive mechanical contact with the surface. An estimation of the tip change would allow the user to assess the quality during imaging. In this work, we introduce a method for tip radius evaluation based on the nonlinear dynamic response of the AFM cantilever. A nonlinear fitting procedure is used to match several curves with softening nonlinearity in the noncontact regime. By performing measurements in this regime, we are able to maximize the influence of the tip radius on the AFM probe response, and this can be exploited to estimate with good accuracy the AFM tip radius.Micro and Nano EngineeringDynamics of Micro and Nano System
The Anthropozoic era revisited
No full textThis paper explains in some detail the poorly known proposal of Stoppani (1873) regarding the Anthropozoic era, whose beginning was defined by the first traces of human presence on Earth. This author set the stratigraphical bases for the definition of the ‘human era’, but the proposal had two main weaknesses: the dismissal of biological evolution and the lack of an absolute chronology. Further developments in radiometric/palaeomagnetic dating and the elucidation of the main trends and timing of human evolution have provided the necessary information to update the original Anthropocene proposal in chronological terms, maintaining Stoppani’s original definition and stratigraphic markers. This updated proposal follows the rules of the International Stratigraphic Guide and situates the beginning of the Anthropozoic era at the beginning of the Quaternary, the time at which the first human fossils, corresponding to the first species of the genus Homo and corresponding cultural manifestations have been identified and dated. Therefore, the new Anthropozoic era would follow the Cenozoic era, which ended with the Neogene period. Defined in this way, the Quaternary period and its Pleistocene and Holocene epochs would be situated in the new Anthropozoic era. The main strengths and weaknesses of the updated Anthropozoic version are discussed. It is suggested that the updated Anthropozoic proposal might be fully elaborated to evaluate whether it should be submitted to the International Commission on Stratigraphy and the International Union of Geological Sciences for formalization. © 2020 Lethaia Foundation. Published by John Wiley & Sons LtdPeer reviewe
Intrinsic frame transport for a model of nematic liquid crystal
No full textWe present a computer simulation study of the dynamical properties of a nematic liquid crystal model. The diffusional motion of the nematic director is taken into account in our calculations in order to give a proper estimate of the transport coefficients, Differently from other groups we do not attempt to stabilize the director through rigid constraints or applied external fields. We instead define an intrinsic frame which moves along with the director at each step of the simulation, The transport coefficients computed in the intrinsic frame are then compared against the ones calculated in the fixed laboratory frame, to show the inadequacy of the latter for systems with less than 500 molecules, Using this general scheme on the Gay-Berne liquid crystal model, we evidence the natural motion of the director and attempt to quantify its intrinsic time scale and size dependence. Through extended simulations of systems of different size we calculate the diffusion and viscosity coefficients of this model and compare our results with values previously obtained with fixed director
Understanding the U.S. distribution of wealth
No full textThis article describes the current state of economic theory intended to explain the unequal distribution of wealth among U.S. households. The models reviewed are heterogeneous agent versions of standard neoclassical growth models with uninsurable idiosyncratic shocks to earnings. The models endogenously generate differences in asset holdings as a result of the household's desire to smooth consumption while earnings fluctuate. Both of the dominant types of models--dynastic and life cycle models--reproduce the U.S. wealth distribution poorly. The article describes several features recently proposed as additions to the theory based on changes in earnings, including business ownership, higher rates of return on high asset levels, random capital gains, government programs to guarantee a minimum level of consumption, and changes in health and marital status. None of these features has been fully analyzed yet, but they all seem to have potential to move the models in the right direction.Wealth
Constrained efficiency in the neoclassical growth model with uninsurable idiosyncratic shocks
No full textWe investigate the welfare properties of the one-sector neoclassic growth model with uninsurable idiosyncratic shocks. We focus on the constrained efficiency notion of the general equilibrium literature, and we demonstrate constrained inefficiency for our model. We provide a characterization of constrained efficiency that uses the first-order condition of a constrained planner's problem that points to the margins of relevance for whether capital is too high or too low: the income composition of the (consumption-)poor. We calibrate our benchmark model parameters governing idiosyncratic risks to the U.S. earnings and wealth distribution, and for this distribution the income of the poor is mainly composed of labor earnings. We compute the constrained-efficient allocations - including transition dynamics - for our model economy, and we conclude that the long-run capital stock in a laissez-faire world is not only too low, but much too low. We also show that one can find parameterizations with different qualitative features: in one case, the steady-state capital stock is too high, and in another case no steady state exists.Constrained efficiency, idiosyncratic risks, neoclassical growth model
CARMA-F
No full textCARMA-F (CARibbean MAngroves-Fossil) is a dataset that gathers the published fossil pollen records of mangrove taxa from the Caribbean region. The latest update includes nearly 90 localities ranging from the Late Cretaceous to the Pliocene. This dataset has been compiled to facilitate the study of the origin, evolution and diversification of Caribbean mangroves, along with the main environmental drivers involved. The data contained in CARMA-F have been used in a collection of papers by the author organized chronologically that discuss the Eocene origin, the Eocene/Oligocene evolutionary turnover and the Neogene diversification of these iconic tropical/subtropical coastal ecosystems, as occurred in the Neotropical Caribbean region. CARMA-F is provided as a spreadsheet and is open to modifications to adapt it to the particular interests of each researcher. A detailed description of the dataset in available at https://www.mdpi.com/2223-7747/12/22/3852. The dataset remains open to further updates, as new data are published/retrieved.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV
CARMA-F
No full textCARMA-F (CARibbean MAngroves-Fossil) is a dataset that gathers the published fossil pollen records of mangrove taxa from the Caribbean region. The latest update includes nearly 90 localities ranging from the Late Cretaceous to the Pliocene. This dataset has been compiled to facilitate the study of the origin, evolution and diversification of Caribbean mangroves, along with the main environmental drivers involved. The data contained in CARMA-F have been used in a collection of papers by the author organized chronologically that discuss the Eocene origin, the Eocene/Oligocene evolutionary turnover and the Neogene diversification of these iconic tropical/subtropical coastal ecosystems, as occurrent in the Neotropical Caribbean region. CARMA-F is provided as a spreadsheet and is open to modifications to adapt it to the particular interests of each researcher. A detailed description of the dataset in available as a preprint (https://doi.org/10.20944/preprints202310.2106.v1) and will be published soon in the journal Plants. The dataset remains open to further updates, as new data are published/retrieved.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV
CARMA-F
No full textCARMA-F (CARibbean MAngroves-Fossil) is a dataset that gathers the published fossil pollen records of mangrove taxa from the Caribbean region. The latest update includes nearly 90 localities ranging from the Late Cretaceous to the Pliocene. This dataset has been compiled to facilitate the study of the origin, evolution and diversification of Caribbean mangroves, along with the main environmental drivers involved. The data contained in CARMA-F have been used in a collection of papers by the author organized chronologically that discuss the Eocene origin, the Eocene/Oligocene evolutionary turnover and the Neogene diversification of these iconic tropical/subtropical coastal ecosystems, as occurred in the Neotropical Caribbean region. CARMA-F is provided as a spreadsheet and is open to modifications to adapt it to the particular interests of each researcher. A detailed description of the dataset in available at https://www.mdpi.com/2223-7747/12/22/3852. The dataset remains open to further updates, as new data are published/retrieved.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV
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