Lifted Most Probable Explanation

Author(s):  
Tanya Braun ◽  
Ralf Möller

The fact that a substance through which Röntgen rays from a focus tube are passing becomes itself a source of secondary Röntgen rays has long- been known. The most probable explanation was given by Prof. Sir J. J. Thomson. If a Röntgen pulse is due to the acceleration of a charged electron, then if the electrons in the atom are free to move under the action of the electromagnetic forces in the wave front of the primary Röntgen pulse, their motion will be accelerated during the passage of the latter through the atom, and they will themselves become sources of secondary Röntgen radiation. Considering only a single electron, the intensity of the secondary radiation at any angle α with the direction of motion will be proportional to sin 2 α . If the primary beam is unpolarised, the motion of the electron may have any direction in the plane at right angles to the primary beam. The intensity of the scattered radiation in the direction θ with the primary beam is thus the mean of all the values of sin 2 α for that direction. It can easily be shown that this is proportional to 1 + cos 2 θ . If I' θ is the intensity of the scattered radiation in the direction θ , we thus have I' θ = I' π /2 (1 + cos 2 θ ).


Paleobiology ◽  
1994 ◽  
Vol 20 (3) ◽  
pp. 362-367 ◽  
Author(s):  
William I. Ausich ◽  
David L. Meyer

Potential hybrid fossil crinoids, Eretmocrinus magnificus x Eretmocrinus praegravis, are identified from the Lower Mississippian Fort Payne Formation of south-central Kentucky. These are the first fossil hybrid crinoids identified, and one of very few examples of hybrids recognized in the fossil record. Eretmocrinus magnificus x E. praegravis specimens have shapes and calyx plate sculpturing that are morphologically intermediate between well-defined, distinct parent species. Suspected hybrids occur at localities where parent species co-occur and where the parent species are the most abundant; the hybrids occur at what may have been the distributional margins of the parent species; and the mixture of characters on suspected hybrids seems to be morphogenetically partitioned. Parent species are derived from separate lineages within Eretmocrinus, and hybridization is the most probable explanation for these morphologically intermediate specimens. This example highlights the need to consider hybridization as a potential interpretation of intermediate morphologies among fossils and raises questions concerning the impact of hybridization for our interpretation of the fossil record and the role of hybridization in the evolutionary process.


2006 ◽  
Vol 453 (3) ◽  
pp. L35-L37 ◽  
Author(s):  
E. A. Dorfi ◽  
A. Gautschy ◽  
H. Saio

2011 ◽  
Vol 16 (1) ◽  
pp. 137-159
Author(s):  
Ülar Ploom

The aim of the present article is to study some aspects of subversive rhetoric in the poetry of Juhan Viiding (1948–1995), one of Estonia’s most admired and cherished poets and actors whose “Complete Poetry” (edited by Hasso Krull) includes texts written between 1968 and 1994, published either in collections (until 1978, under the pseudonym of Jüri Üdi, which translates as George Marrow in English) or separately in newspapers and magazines. It is important to mention that Juhan Viiding often read and sang his texts (accompanied on the piano by Tõnis Rätsep, a friend and colleague from the Estonian Drama Theatre), quite a few of which are recorded on cassette and CD. Üdi/Viiding was and continues to be widely read, quoted, imitated and discussed by his Estonian readers, fellow poets, intellectuals and critics. However, despite the fact that Viiding’s poetry has been translated into sixteen languages, according to Aare Pilv’s “Juhan Viidingu ja Jüri Üdi bibliograafia” (Pilv 2010: 170–175), Viiding has not achieved the sort of fame abroad which he enjoys in Estonia. Indeed, the volume of articles and essays written in Estonian on Viiding’s poetry is not equalled by writing in other languages. Reviews written in English and Russian are mostly by Estonian critics or Russian critics from Estonia (ib. 196–208). Of course, poetry in general does not submit easily to being translated, but in Üdi/Viiding’s case we are dealing with a kind of poetic which makes the process even more complicated, perhaps also partly unachievable. This seems to be the most probable explanation for the asymmetry of Üdi/Viiding’s poetic reputation. So, apart from the peculiar charm of his poetry, with its highly intricate poly-semantic spectrum which calls out for discussion of the organising principles of his texts, I am writing this article in the hope that more foreign critics will take an interest in this exceptional poet and more poets who write in other languages will rise to the challenge of translating his texts or providing their own original pieces of creative writing in Üdi/Viiding’s wake.


1982 ◽  
Vol 14 (1) ◽  
pp. 1-6 ◽  
Author(s):  
J. Richard Udry ◽  
Fred R. Deven ◽  
Samuel J. Coleman

SummaryParallel analyses of recent data from the United States, Thailand, Belgium, and Japan all confirm the finding that female age and not male age is the more important contributor to the decline in frequency of marital intercourse during the childbearing ages. The most probable explanation is the decline in female (but not male) androgen levels during the age span examined.


Perception ◽  
1978 ◽  
Vol 7 (5) ◽  
pp. 507-512 ◽  
Author(s):  
Jennifer G Wishart ◽  
T G R Bower ◽  
Jane Dunkeld

Reaching for noise-making objects presented in darkness declines, then recovers, during infancy. The most probable explanation of this U-shaped function would seem to involve changes in reaching, changes in the perception of success, and changes in the body schema. There is no need to postulate any U-shaped change within the auditory system.


1968 ◽  
Vol 21 (12) ◽  
pp. 2933
Author(s):  
HF Ryan

Chloroform in acetone or ethanol solvent was rapidly hydrolysed to carbon monoxide and formate by Amberlite XE-78 in the OH-form. Hydroxyl sites on the resin were converted into chloride. The apparent loss in capacity of the resin which occurs during the reaction cannot be wholly accounted for by production of formate. The most probable explanation for the phenomenon is the adsorption of carbon trichloride anions at resin sites. Carbon tetrachloride in ketonic solvents also gave carbon monoxide and formate in the presence of the OH-form of the resin, but in alcohol or ether solvent carbon dioxide and phosgene were formed.


Jurnal MIPA ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 71
Author(s):  
Era Monalisa ◽  
Feky Recky Mantiri ◽  
Hanry Jefri Lengkong

Penelitian ini bertujuan untuk menganalisis variasi interspesies kelelawar Pteropus sp. dan menjelaskan hubungan filogeni Pteropus sp. dengan spesies Pteropus lain yang terdata di GenBank berdasarkan Gen COI. Analisis sekuens menggunakan Geneious v5.6.4 dan menunjukkan adanya variasi interspesies sekuens gen COI pada ketiga sampel Pteropus sp. yang ditunjukkan oleh adanya perbedaan 5 pasang basa nukleotida pada urutan sekuens sampel nomor 157, 160, 421, 427 dan 652 dengan jarak genetik 0,006. Filogeni Ke-3 sampel kelelawar Pteropus sp. dengan spesies Pteropus lain dilakukan menggunakan MEGAX. Hasil filogeni menunjukkan bahwa sampel yang diteliti merupakan kelelawar dari genus Pteropus tetapi belum dapat dipastikan spesiesnya, karena ketika pohon filogeni dikonstruksikan membentuk satu klaster sendiri. Penjelasan dari proses tersebut adalah penyortiran garis keturunan yang tidak lengkap dan terjadinya hibridisasi, serta diduga bahwa primer yang digunakan kurang mampu dalam membedakan variasi intrespesies terhadap kelelawar genus PteropusThis study aimed to analyze the interspecificvariations of bats from Pteropus sp. and describethe phylogenetic relationship of Pteropus sp. with other Pteropus species recorded inGenBank based on the COI gene. Sequenceanalysis by Geneious v5.6.4 showed interspecificvariations of COI gene sequences in all threesamples of Pteropus sp. which was indicated byvariations in 5 nucleotide base pairs in thesequences number 157, 160, 421, 427 and 652with 0.006 of genetic distance value. Phylogeneticof the 3 bat samples of Pteropus sp. with otherPteropus species was carried out by MEGAX.Phylogenetic analyses showed that the samplesstudied are bats of the genus Pteropus, but theexact species cannot be determined because thesamples were grouped in the same cluster duringphylogenetic tree construction. The most probable explanation for this observation is hybridization between two different Pteropus spesies and also it is assumed that the primersused are not capable to distinguish interspecificvariations of the bats from the Pteropus genusPenelitian ini bertujuan untuk menganalisis variasi interspesies kelelawar Pteropus sp. dan menjelaskan hubungan filogeni Pteropus sp. dengan spesies Pteropus lain yang terdata di GenBank berdasarkan Gen COI. Analisis sekuens menggunakan Geneious v5.6.4 dan menunjukkan adanya variasi interspesies sekuens gen COI pada ketiga sampel Pteropus sp. yang ditunjukkan oleh adanya perbedaan 5 pasang basa nukleotida pada urutan sekuens sampel nomor 157, 160, 421, 427 dan 652 dengan jarak genetik 0,006. Filogeni Ke-3 sampel kelelawar Pteropus sp. dengan spesies Pteropus lain dilakukan menggunakan MEGAX. Hasil filogeni menunjukkan bahwa sampel yang diteliti merupakan kelelawar dari genus Pteropus tetapi belum dapat dipastikan spesiesnya, karena ketika pohon filogeni dikonstruksikan membentuk satu klaster sendiri. Penjelasan dari proses tersebut adalah penyortiran garis keturunan yang tidak lengkap dan terjadinya hibridisasi, serta diduga bahwa primer yang digunakan kurang mampu dalam membedakan variasi intrespesies terhadap kelelawar genus Pteropus


2015 ◽  
Vol 53 ◽  
pp. 699-720 ◽  
Author(s):  
Johan Kwisthout

The problem of finding the most probable explanation to a designated set of variables given partial evidence (the MAP problem) is a notoriously intractable problem in Bayesian networks, both to compute exactly and to approximate. It is known, both from theoretical considerations and from practical experience, that low tree-width is typically an essential prerequisite to efficient exact computations in Bayesian networks. In this paper we investigate whether the same holds for approximating MAP. We define four notions of approximating MAP (by value, structure, rank, and expectation) and argue that all of them are intractable in general. We prove that efficient value-approximations, structure-approximations, and rank-approximations of MAP instances with high tree-width will violate the Exponential Time Hypothesis. In contrast, we show that MAP can sometimes be efficiently expectation-approximated, even in instances with high tree-width, if the most probable explanation has a high probability. We introduce the complexity class FERT, analogous to the class FTP, to capture this notion of fixed-parameter expectation-approximability. We suggest a road-map to future research that yields fixed-parameter tractable results for expectation-approximate MAP, even in graphs with high tree-width.


Sign in / Sign up

Export Citation Format

Share Document