102 research outputs found
Paleogenomics of Animal Domestication
No full textStarting with dogs, over 15,000 years ago, the domestication of animals has been central in the development of modern societies. Because of its importance for a range of disciplines—including archaeology, biology, and the humanities—domestication has been studied extensively. This chapter reviews how the field of paleogenomics, has, and will continue to, revolutionise our understanding of animal domestication. We discuss how the recovery of ancient DNA from archaeological remains is allowing researchers to overcome inherent shortcomings arising from the analysis of modern DNA alone. In particular, we show how DNA, extracted from ancient substrates, has proven to be a crucial source of information to reconstruct the geographic and temporal origin of domestic species. We also discuss how ancient DNA is being used by geneticists and archaeologists to directly observe evolutionary changes linked to artificial and natural selection to generate a richer understanding of this fascinating process
An LaF-CMAES hybrid for optimization in multi-modal search spaces
No full textOptimization in multi-modal search spaces requires both exploration and exploitation. The role of exploration is to find promising attraction basins, and the role of exploitation is to find the best solutions (i.e. the local optima) within these attraction basins. In many search techniques, the balance between exploration and exploitation can be adjusted by various parameter settings. An alternative approach is to develop (hybrid) techniques with distinct mechanisms for the task of exploration and the task of exploitation. We believe this second approach can be simpler and more effective. The presented LaF-CMAES hybrid involves relatively few design decisions (e.g. parameter selections), and it delivers highly competitive performance across a benchmark set of multi-modal functions
Inferring bottlenecks from genome-wide samples of short sequence blocks
No full textThe advent of the genomic era has necessitated the development of methods capable of analyzing large volumes of genomic data efficiently. Being able to reliably identify bottlenecks—extreme population size changes of short duration—not only is interesting in the context of speciation and extinction but also matters (as a null model) when inferring selection. Bottlenecks can be detected in polymorphism data via their distorting effect on the shape of the underlying genealogy. Here, we use the generating function of genealogies to derive the probability of mutational configurations in short sequence blocks under a simple bottleneck model. Given a large number of nonrecombining blocks, we can compute maximum-likelihood estimates of the time and strength of the bottleneck. Our method relies on a simple summary of the joint distribution of polymorphic sites. We extend the site frequency spectrum by counting mutations in frequency classes in short sequence blocks. Using linkage information over short distances in this way gives greater power to detect bottlenecks than the site frequency spectrum and potentially opens up a wide range of demographic histories to blockwise inference. Finally, we apply our method to genomic data from a species of pig (Sus cebifrons) endemic to islands in the center and west of the Philippines to estimate whether a bottleneck occurred upon island colonization and compare our scheme to Li and Durbin’s pairwise sequentially Markovian coalescent (PSMC) both for the pig data and using simulations. © 2015 by the Genetics Society of America
LASER ABSORPTION SPECTROSCOPY OF LaF: ANALYSIS OF THE TRANSITION
No full textWork supported by AFOSR under grant F19628-90-c-025. H. Schall, C. Linton, and R. W. Field J. Mol. Spectrose. 100, 437-448 (1985): B. Simard and A. M. James, J. Chem. Phys. 97, 4669-4675 (1992)Author Institution: Department of Chemistry, Emory UniversityLaser absorption spectrum of the LaF (2,0), (1,0), (2,1), and (3,2) bands was recorded. Gas phase LaF was obtained by heating a mixture of a 0.2 g of La metal and 0.3 g of powder to 1900K. In order to modulate the absorption signal, the concentration of LaF was varied by passing a 25 kHz discharge (80-100W, 0.5A peak current) through the vapor. Under these conditions the Tantalum heating tube used to vaporize the sample also acted as a hollow cathode. The B-X band system was observed previously In analyzing the spectrum, we have combined absorption data with that from the Reference. Accurate molecular constants (in ) and internuclear distance (in nm) for the state are: Rotational perturbations were evident in the levels. The pattern of the state perturbations was shown to be a consequence of the interaction with the state by using the experimental value of (see Reference) and estimated value of for the triplet state. The principal new results to emerge from this investigation are the equilbrium constants for the and states of LaF
ENERGY LINKAGE OF THE SINGLET AND TRIPLET MANIFOLDS IN LaF
No full textAuthor Institution: Department of Chemistry, Massachusetts Institute of Technology Cambridge; Department of Physics, University Of New Brunswick FrederictonA combination of dispersed laser induced fluorescence and Doppler-limited fluorescence excitation spectroscopy has been used to examine the electronic spectrum of the LaF molecule. Dispersed fluorescence experiments have located the state at above the state. In addition, two Q = 2 levels are found at and . A new transition was observed with and . The results of these initial experiments will be reported and the energy level diagram will be discussed in terms of Ligand Field Theory
LAF CAB 5
No full textThis little book shows OF in an oval on its yellow cover. The fables presented are OF, OR, L'Ane et le Chien, and Le Cochet, le Chat et le Souriceau. The best illustration may be that for OR (9). The same little mouse who appeared on the back of Volume III is on the last page of this book.La Fontain
LAF CAB 9
No full textThis little book shows Le Lièvre et les Grenouilles in an oval on its red cover. The other fables presented are Le Petit Poisson et le Pécheur, Le Renard et le Bouc, and Le Loup devenu Berger. This book attempts a two-page spread for illustrating the title-fable (16-17).La Fontain
LAF CAB 6
No full textThis little book shows Le Lion et le Moucheron in an oval on its blue cover. The other fables presented are SS, L'Oeil du Maitre, and Les Médicins. In fact, the lion and his mosquito get two more illustrations, and the insect is much more visible on them than on the cover.La Fontain
LAF CAB 4
No full textThis little book shows LM in an oval on its red cover. The fables presented are LM, AD, Les Animaux Malades de la Peste, and TB. There is a fine illustration of AD including a rejoicing ant and some blood on the hunter's foot (9). There are also good illustrations of the sick lion and reluctant ass (16-17).La Fontain
LAF CAB 12
No full textThis little book shows La Fontaine himself in an oval on its blue-gray cover. This album contains no fables. It has instead a dictionary of all the words in bold print in the first eleven albums, and then it has a full T of C featuring the names of the fables in each volume. On 16-17 there is a very pretty two-page spread showing the fox and wolf reading books under a tree, while other animals look on.La Fontain
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