113 research outputs found
Climate change underlies global demographic, genetic, and cultural transitions in pre-Columbian southern Peru
No full textSeveral archaeological studies in the Central Andes have pointed at the temporal coincidence of climatic fluctuations (both long- and short-term) and episodes of cultural transition and changes of socioeconomic structures throughout the pre-Columbian period. Although most scholars explain the connection between environmental and cultural changes by the impact of climatic alterations on the capacities of the ecosystems inhabited by pre-Columbian cultures, direct evidence for assumed demographic consequences is missing so far. In this study, we address directly the impact of climatic changes on the spatial population dynamics of the Central Andes. We use a large dataset of pre-Columbian mitochondrial DNA sequences from the northern Rio Grande de Nasca drainage (RGND) in southern Peru, dating from ∼840 BC to 1450 AD. Alternative demographic scenarios are tested using Bayesian serial coalescent simulations in an approximate Bayesian computational framework. Our results indicate migrations from the lower coastal valleys of southern Peru into the Andean highlands coincident with increasing climate variability at the end of the Nasca culture at ∼640 AD. We also find support for a back-migration from the highlands to the coast coincident with droughts in the southeastern Andean highlands and improvement of climatic conditions on the coast after the decline of the Wari and Tiwanaku empires (∼1200 AD), leading to a genetic homogenization in the RGND and probably southern Peru as a whole.Lars Fehren-Schmitz, Wolfgang Haak, Bertil Mächtle, Florian Masch, Bastien Llamas, Elsa Tomasto Cagigao, Volker Sossna, Karsten Schittek, Johny Isla Cuadrado, Bernhard Eitel, and Markus Reinde
Guest-host electro-optic switching in spin-coated polymer ferroelectric liquid crystal film
No full textThis article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Shoji Okazaki, Sadahito Uto, Masanori Ozaki, Katsumi Yoshino, Kent Skarp, and Bertil Helgee, Appl. Phys. Lett. 71, 3373 (1997) and may be found at https://doi.org/10.1063/1.120399.We have proposed an electro-optic effect in dichroic-dye-doped polymer ferroelectric liquid crystal thin films prepared by a spin-coating technique. A high-quality homeotropically aligned film has been realized. Guest-host type electro-optic switching is confirmed in the dye-doped film, and basic properties such as electric field dependence of the response time are studied
Electro-optic switching in spin-coated ferroelectric mesomorphic polymer films and its analysis
No full textThis article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Sadahito Uto, Hiroshi Moritake, Masanori Ozaki, Kent Skarp, and Bertil Helgee, Journal of Applied Physics 79, 4444 (1996) and may be found at https://doi.org/10.1063/1.361754.Thin films of a chiral side‐chain polymer with a ferroelectric phase were deposited on a substrate by spin coating. Electro‐optic switching in the films were observed by applying an external field using in‐plane electrodes. Characteristics of the switching are presented, together with an analysis of the switching dynamics that takes into account the inhomogenous field distribution in the active area
Indrukwekkend en wereldberoemd: Natuursteencollecties deel 16
No full textWido Quist bracht in september samen met Jan van ’t Hof, Rutger Morelissen en Bertil van Os, natuursteenkenners en -liefhebbers van de Rijksdienst voor het Cultureel Erfgoed, een bezoek aan Londen, Oxford en Cambridge om daar een aantal indrukwekkende en wereldberoemde natuursteencollecties te bekijken. In dit artikel meer over de collectie van het Natural History Museum in Londen. In latere delen van deze serie zullen ook de Corsi-collectie te Oxford en de Watson-collectie te Cambridge worden besproken.Heritage & Technolog
MSAProbs-MPI: parallel multiple sequence aligner for distributed-memory systems
No full textThis is a pre-copyedited, author-produced version of an article accepted for publication in Bioinformatics following peer review. The version of recordJorge González-Domínguez, Yongchao Liu, Juan Touriño, Bertil Schmidt; MSAProbs-MPI: parallel multiple sequence aligner for distributed-memory systems, Bioinformatics, Volume 32, Issue 24, 15 December 2016, Pages 3826–3828, https://doi.org/10.1093/bioinformatics/btw558is available online at: https://doi.org/10.1093/bioinformatics/btw558[Abstracts] MSAProbs is a state-of-the-art protein multiple sequence alignment tool based on hidden Markov models. It can achieve high alignment accuracy at the expense of relatively long runtimes for large-scale input datasets. In this work we present MSAProbs-MPI, a distributed-memory parallel version of the multithreaded MSAProbs tool that is able to reduce runtimes by exploiting the compute capabilities of common multicore CPU clusters. Our performance evaluation on a cluster with 32 nodes (each containing two Intel Haswell processors) shows reductions in execution time of over one order of magnitude for typical input datasets. Furthermore, MSAProbs-MPI using eight nodes is faster than the GPU-accelerated QuickProbs running on a Tesla K20. Another strong point is that MSAProbs-MPI can deal with large datasets for which MSAProbs and QuickProbs might fail due to time and memory constraints, respectively
Global economic crisis and regional disparities
No full textIn international trade theory is not uncommon case that development of international trade compared with the development of regional cooperation. The most famous author in this field is a Swedish economist Bertil Ohlin, which theory is exactly defined by a comparative analysis of general equilibrium. Similar approach can be analyzed and economic development of the global (financial) crisis
Template for a "Research Footprint": An overview of a researcher's online academic presence
No full text<p>What do you look like as a researcher, when someone external to your institute looks you up online?</p>
<p>A "Research Footprint" provides a researcher with an immediate and visual overview of their online academic presence. We show what the researcher's metrics look like on the most widely used citation databases: Scopus, Web of Science (WoS) and Google Scholar. We limit the Research Footprint to the most basic personal metrics: Number of publications, number of open access publications, number of citations, times cited per year, and the h-index. We check whether the researcher has created and maintained the most important author identifiers: ORCID, ScopusID and ResearcherID (Publons), and linked them to our institutional repository based on PURE.</p>
<p>We collect all this data as a kicking off point for a 1-on-1 discussion with the researcher. In that discussion we go through the importance of Author Identifiers and check whether all their publications are properly claimed on Scopus, WoS and Google Scholar. Finally, we give them the tools to maintain their profiles on their own to ensure that when external parties look them up, they find an accurate representation of the researcher's publication data. </p>
<p>These are the template files we developed at the University of Southern Denmark to generate the Research Footprint. They include a Disclaimer and a GDPR statement. The publication data can be collected in the provided Excel file and then copied over to the Word file. </p>
How can we learn whether firm policies are working in africa ? challenges (and solutions?) for experiments and structural models
No full textFirm productivity is low in African countries, prompting governments to try a number of active policies to improve it. Yet despite the millions of dollars spent on these policies, we are far from a situation where we know whether many of them are yielding the desired payoffs. This paper establishes some basic facts about the number and heterogeneity of firms in different sub-Saharan African countries and discusses their implications for experimental and structural approaches towards trying to estimate firm policy impacts. It shows that the typical firm program such as a matching grant scheme or business training program involves only 100 to 300 firms, which are often very heterogeneous in terms of employment and sales levels. As a result, standard experimental designs will lack any power to detect reasonable sized treatment impacts, while structural models which assume common production technologies and few missing markets will be ill-suited to capture the key constraints firms face. Nevertheless, the author suggests a way forward which involves focusing on a more homogeneous sub-sample of firms and collecting a lot more data on them than is typically collected.Microfinance,Small Scale Enterprise,E-Business,ICT Policy and Strategies,Banks&Banking Reform
[Myanmar] Covid-19’s hidden threat in Myanmar
No full textAuteur : Bertil Lintner. A former correspondent with the Far Eastern Economic Review and the author of several books on Burma, North Korea, and organized crime in the Asia-Pacific. Production : Asia Times. Initialement, journal papier fondé à Bangkok en 1995, devenu la seule plate-forme de nouvelles numériques multilingue et panasiatique au monde. Outre l’anglais, Asia Times publie en caractères chinois traditionnels et simplifiés, indonésien, vietnamien, coréen, philippin et arabe. Diffu..
Prophecy and politics in the Old Testament
No full textThe purpose of this paper is to discuss aspects which concern the religious legitimation of the state, with a focus on the period of the Israelite monarchy, partly because it is during this particular period—the reigns of David and Solomon, and the time of the divided kingdom down to the exile—that the political organization of Israel may safely be called a state, and partly because the golden age of the prophetic movement falls precisely in this period. The author provides a sketch of the historical and ideological background and then says something about three different groups of prophets: the professional cultic prophets, the early Yahwistic prophets of the type of Elijah and Elisha, and the great prophets
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