258,706 research outputs found
Quantitative and Econometric Methodologies in the Study of Civil War
This chapter provides an overview of the quantitative study of civil war, focusing on the development of quantitative conflict studies, the basics of the quantitative method, the prominent sources of civil conflict data, and the strengths and weaknesses of using quantitative methods to analyse civil war
Terminal states of thermocapillary migration of a planar droplet at moderate and large Marangoni numbers
In this paper, thermocapillary migration of a planar droplet at moderate and
large Marangoni numbers is investigated analytically and numerically. By using
the dimension-analysis method, the thermal diffusion time scale is determined
as the controlling one of the thermocapillary droplet migration system. During
this time, the whole thermocapillary migration process is fully developed. By
using the front-tracking method, the steady/unsteady states as the terminal
ones at moderate/large Marangoni numbers are captured in a longer time scale
than the thermal diffusion time scale. In the terminal states, the
instantaneous velocity fields in the unsteady migration process at large
Marangoni numbers have the forms of the steady ones at moderate Marangoni
numbers. However, in view of the former instantaneous temperature fields, the
surface tension of the top surface of the droplet gradually becomes the main
component of the driving force on the droplet after the inflection point
appears. It is different from that the surface tension of the bottom surface of
the droplet is the main component of the driving force on the droplet for the
latter ones. The physical mechanism of thermocapillary droplet migration can be
described as the significance of the thermal convection around the droplet is
higher than/just as the thermal conduction across the droplet at large/moderate
Marangoni numbers.Comment: 8 pages, 6 figure
Mesoscale mapping of sediment source hotspots for dam sediment management in data-sparse semi-arid catchments
Land degradation and water availability in semi-arid regions are interdependent challenges for management that are influenced by climatic and anthropogenic changes. Erosion and high sediment loads in rivers cause reservoir siltation and decrease storage capacity, which pose risk on water security for citizens, agriculture, and industry. In regions where resources for management are limited, identifying spatial-temporal variability of sediment sources is crucial to decrease siltation. Despite widespread availability of rigorous methods, approaches simplifying spatial and temporal variability of erosion are often inappropriately applied to very data sparse semi-arid regions. In this work, we review existing approaches for mapping erosional hotspots, and provide an example of spatial-temporal mapping approach in two case study regions. The barriers limiting data availability and their effects on erosion mapping methods, their validation, and resulting prioritization of leverage management areas are discussed.BMBF, 02WGR1421A-I, GROW - Verbundprojekt SaWaM: Saisonales Wasserressourcen-Management in Trockenregionen: Praxistransfer regionalisierter globaler Informationen, Teilprojekt 1DFG, 414044773, Open Access Publizieren 2019 - 2020 / Technische UniversitÀt Berli
Anchoring linkage groups of the Rosa genetic map to physical chromosomes with tyramide-FISH and EST-SNP markers
In order to anchor Rosa linkage groups to physical chromosomes, a combination of the Tyramide-FISH technology and the modern molecular marker system based on High Resolution Melting (HRM) is an efficient approach. Although, Tyramide-FISH is a very promising technique for the visualization of short DNA probes, it is very challenging for plant species with small chromosomes such as Rosa. In this study, we successfully applied the Tyramide-FISH technique for Rosa and compared different detection systems. An indirect detection system exploiting biotinylated tyramides was shown to be the most suitable technique for reliable signal detection. Three gene fragments with a size of 1100 pb-1700 bp (Phenylalanine Ammonia Lyase, Pyrroline-5-Carboxylate Synthase and Orcinol O-Methyl Transferase) have been physically mapped on chromosomes 7, 4 and 1, respectively, of Rosa wichurana. The signal frequency was between 25% and 40%. HRM markers of these 3 gene fragments were used to include the gene fragments on the existing genetic linkage map of Rosa wichurana. As a result, three linkage groups could be anchored to their physical chromosomes. The information was used to check for synteny between the Rosa chromosomes and Fragaria
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