scholarly journals Relative time scales reveal multiple origins of parallel disjunct distributions of African caecilian amphibians

2007 ◽  
Vol 3 (5) ◽  
pp. 505-508 ◽  
Author(s):  
Simon P Loader ◽  
Davide Pisani ◽  
James A Cotton ◽  
David J Gower ◽  
Julia J Day ◽  
...  
Keyword(s):  
Time Scales ◽  
Molecular Data ◽  
Relative Time ◽  
Temporal Dimension ◽  
Parallel Patterns ◽  
Common Cause ◽  
Absolute Time ◽  
Multiple Origins ◽  
Relative Dating ◽  
East West

Parallel patterns of distribution in different lineages suggest a common cause. Explanations in terms of a single biogeographic event often imply contemporaneous diversifications. Phylogenies with absolute time scales provide the most obvious means of testing temporal components of biogeographic hypotheses but, in their absence, the sequence of diversification events and whether any could have been contemporaneous can be tested with relative date estimates. Tests using relative time scales have been largely overlooked, but because they do not require the calibration upon which absolute time scales depend, they make a large amount of existing molecular data of use to historical biogeography and may also be helpful when calibration is possible but uncertain. We illustrate the use of relative dating by testing the hypothesis that parallel, disjunct east/west distributions in three independent lineages of African caecilians have a common cause. We demonstrate that at least two biogeographic events are implied by molecular data. Relative dating analysis reveals the potential complexity of causes of parallel distributions and cautions against inferring common cause from common spatial patterns without considering the temporal dimension.

scholarly journals Albanian Aorist and Time Reference Points

2020 ◽  
Vol 10 (3) ◽  
pp. 115
Author(s):  
Muhamet Reçica ◽  
Naser Pajaziti
Keyword(s):  
Reference Point ◽  
Reference Points ◽  
The Other ◽  
Temporal Relations ◽  
Time Dimension ◽  
Relative Time ◽  
Absolute Time ◽  
Temporal System ◽  
The Absolute

Topics related to the structure of the temporal system of Albanian language always give opportunities for new discussions to deal with certain aspects related to various forms of this system, and one of them is the aorist, as a tense containing many semantic, temporal, aspectual, stylistic values, etc. The relationships that exist between the verbal tenses in this system within the absolute time-relative time dimension, which relate to the independent or dependent use of temporal forms against one another in different discoursing contexts, make up an interpretation-based approach to interest. Hence, the essential objective of this paper will be specifically the relations of the Albanian aorist to the other verbal forms, always observed with a time reference point, to illuminate the character of these purely temporal relations against each other under all circumstances of the actions that take place and are displayed by verbal forms in different contexts, relying on the corpus of examined materials.

scholarly journals Southeastern U.S. Tornado Outbreak Likelihood Using Daily Climate Indices

2020 ◽  
Vol 33 (8) ◽  
pp. 3229-3252
Author(s):  
Matthew C. Brown ◽  
Christopher J. Nowotarski
Keyword(s):  
Time Scales ◽  
North Atlantic ◽  
Climate Indices ◽  
Regional Environment ◽  
Self Organizing Maps ◽  
Upper Level ◽  
Climate Scale ◽  
Climate Studies ◽  
Tornado Outbreaks ◽  
East West

AbstractThis study investigates relationships between climate-scale patterns and seasonal tornado outbreaks across the southeastern United States. Time series of several daily climate indices—including Arctic Oscillation (AO), North Atlantic Oscillation (NAO), Pacific–North American (PNA) pattern, east/west Pacific Oscillation (EPO/WPO), and both raw and detrended Gulf of Mexico SST anomalies (SSTA/SSTAD)—are collected in advance of Southeast severe convective days and grouped using self-organizing maps (SOMs). Spatiotemporal distributions of storm reports within nodes are compared to seasonal climatology, and the evolution of the regional environment for nodes associated with outbreaks is analyzed to provide physical justification for such associations. This study confirms findings from several tornado-related climate studies in the literature, while also identifying a number of new patterns associated with Southeast tornado outbreaks. Both the AO and NAO are relevant across all seasons, especially on lead time scales of 1–2 months, while SSTA/SSTADs are relevant on smaller time scales. The physical connection between these patterns and the regional storm environment is largely related to alterations of upper-level circulation and jet stream patterns, which in turn influence deep- and low-level shear, inland transport of moisture and instability, and other regional characteristics pertinent to tornado outbreaks. These results suggest that climate-scale variability can modulate and potentially be used to predict regional storm environments and their likelihood to produce tornado outbreaks across the Southeast.

Application of the Handysurf E-35B electronic profilometer for the study of weathering micro-relief in glacier forelands in SE Iceland

2015 ◽  
Vol 65 (3) ◽  
pp. 389-401 ◽  
Author(s):  
Maciej Dąbski
Keyword(s):  
Time Scales ◽  
Little Ice Age ◽  
Major Change ◽  
Limited Range ◽  
Ice Age ◽  
Rock Surface ◽  
Schmidt Hammer ◽  
Fine Grained ◽  
Relative Dating ◽  
Roughness Measurements

AbstractThis article presents the results of weathering micro-roughness measurements performed with the use of a Handy-surf E-35B electronic profilometer, a new tool in geomorphological studies. Measurements were performed on glacially abraded basaltic surfaces within the Little Ice Age (LIA) glacial forelands of Hoffelsjökull, Fláajökull, Skálafellsjökull and Virkisjökull in Iceland. Results show a statistical increase in micro-roughness in a direction from the glacial termini to LIA moraines. However, a major change in the micro-roughness of basaltic surfaces only occurs during the first 80 to 100 years since the onset of subaerial weathering. Increase in rock surface micro-roughness is accompanied by an increase in weathering rind thickness and a decrease in Schmidt hammer R-values. Micro-roughness measurements with the use of the Handysurf E-35B can provide insights into initial rates of rock surface micro-relief development. The use of this instrument as a relative dating technique is limited to fine-grained rocks and decadal time-scales of weathering because of the limited range of measureable micro-relief amplitude.

scholarly journals Modified Lorentz transformations and quantum mechanics

2021 ◽  
Author(s):  
Jae-Kwang Hwang
Keyword(s):  
Wave Function ◽  
Quantum Mechanics ◽  
Euclidean Space ◽  
Coordinate System ◽  
Space Time ◽  
Lorentz Transformations ◽  
Relative Time ◽  
Absolute Time ◽  
Time Shape ◽  
The Absolute

Abstract We live in the 4-D Euclidean space. The 4th dimension is assigned as the absolute time (ct) axis and energy axis (cPt = E0) based on 4-dimensional Euclidean space. This 4th dimension can be indirectly felt through the observable relative time (ctl) and observable total energy (cPtl = E). The space-time distance is d(x1x2x3x4) = ctl. The modified Lorentz transformations are introduced by the time-matching of the absolute times in the 4-D Euclidean space. The size of x’ (or Dx’) of the moving object is expanded to the size of x = gx’ (or Dx = gDx’). These modified Lorentz transformations are approximated to the Lorentz transformations as t à tl when v/c << 1 and to the Galilean transformations as v/c is close to zero. The relative time (tl) and energy (E) are defined as the 4-dimensional distance and 4-dimensional volume, respectively. The geometrical space-time shape has the (x1,x2,x3,ct) coordinate system with the metric signature of (+ + + +) but not the (x1,x2,x3,ctl) coordinate system with the metric signature of (+ - - -). Therefore, d(x1x2x3x4)2 = (ctl)2 = (ct)2 +x2 = x12 + x22 + x32 + x42 and V(x1x2x3x4) = E = mc2 = D(ct)Dx1Dx2Dx3 from (x1,x2,x3,x4) of the geometrical space-time shape. The warped shape can be described as the wave function of the quantum mechanics. The instant force action, twin paradox and possible space travel are explained by the absolute time and wave function collapse of the modified Lorentz transformations and quantum mechanics.

Trees, assemblies, chains, and windows

2020 ◽  
Vol 12 (1) ◽  
pp. 8-55
Author(s):  
Ronald W. Langacker
Keyword(s):  
Structure Function ◽  
Time Scales ◽  
Cognitive Grammar ◽  
Unified Approach ◽  
Temporal Dimension ◽  
Linguistic Ability ◽  
Processing Activity ◽  
Dependency Trees ◽  
Different Time Scales

Abstract For describing grammatical organization, metaphors based on a variety of source domains – including trees, networks, chains, paths, and windows – all appear to have some validity. In Cognitive Grammar, they pertain to facets of assemblies, where semantic and phonological structures are connected by relations of symbolization, composition, and categorization. Assemblies have a temporal dimension; consisting in sequenced processing activity that runs concurrently on different time scales, they involve both seriality and hierarchy. In their hierarchical aspect, they are comparable to constituency trees, and in their connections, to dependency trees. Assembly elements, which can be characterized at any level of specificity, are connected in both syntagmatic and paradigmatic relations. A person’s linguistic ability comprises a vast assembly of conventional units, a portion of which are activated as part of the transient assembly constituting a particular expression. Lexicon and grammar effect the implementation of semantic functions – affective, interactive, descriptive, and discursive – which emerge with varying degrees of salience depending on their symbolization by segmental, prosodic, and other means. Assemblies thus make possible a unified approach to processing, structure, function, and use.

Time and Place

Al-Rāzī ◽  
2021 ◽  
pp. 99-120
Author(s):  
Peter Adamson
Keyword(s):  
Relative Time ◽  
Absolute Time ◽  
The World

The final two principles of Razi’s cosmology are time and place, which he considers to be an eternal framework in which the world is created. Both “absolute time” or eternity and “absolute place” or void are seen as independent of bodies or motion. This is shown to be a critique of Aristotelian’s physics inspired by Plato, by way of Galen. The chapter argues that for Razi, Aristotle’s definitions of time and place are accurate but only as concerns “relative” time and place, that is, the time and place of individual bodies. More fundamental are eternal duration and void, which are based on the concepts of time and place found in Plato’s Timaeus.

scholarly journals Multiple origins of deep-sea Asellota (Crustacea: Isopoda) from shallow waters revealed by molecular data

2008 ◽  
Vol 276 (1658) ◽  
pp. 799-808 ◽  
Author(s):  
Michael J Raupach ◽  
Christoph Mayer ◽  
Marina Malyutina ◽  
Johann-Wolfgang Wägele
Keyword(s):  
Shallow Water ◽  
Deep Sea ◽  
Morphological Characters ◽  
Molecular Data ◽  
Multiple Origins ◽  
Morphological Adaptations ◽  
The Family ◽  
Shallow Water Species ◽  
Water Species ◽  
Variable Group

The Asellota are a highly variable group of Isopoda with many species in freshwater and marine shallow-water environments. However, in the deep sea, they show their most impressive radiation with a broad range of astonishing morphological adaptations and bizarre body forms. Nevertheless, the evolution and phylogeny of the deep-sea Asellota are poorly known because of difficulties in scoring morphological characters. In this study, the molecular phylogeny of the Asellota is evaluated for 15 marine shallow-water species and 101 deep-sea species, using complete 18S and partial 28S rDNA gene sequences. Our molecular data support the monophyly of most deep-sea families and give evidence for a multiple colonization of the deep sea by at least four major lineages of asellote isopods. According to our molecular data, one of these lineages indicates an impressive radiation in the deep sea. Furthermore, the present study rejects the monophyly of the family Janiridae, a group of plesiomorphic shallow-water Asellota, and several shallow-water and deep-sea genera ( Acanthaspidia , Ianthopsis , Haploniscus , Echinozone , Eurycope , Munnopsurus and Syneurycope ).

scholarly journals Ephemeris Astronomy Definitions and Constants in General Relativity

1997 ◽  
Vol 165 ◽  
pp. 439-446
Author(s):  
Victor A. Brumberg
Keyword(s):  
General Relativity ◽  
Time Scales ◽  
Absolute Space ◽  
Newtonian Mechanics ◽  
Reference Systems ◽  
Absolute Time ◽  
Astronomical Constants

AbstractCurrently employed definitions of ephemeris astronomy and the system of astronomical constants are based on Newtonian mechanics with its absolute time and absolute space. To avoid any relativistic ambiguities in applying new IAU (1991) resolutions on reference systems (RS) and time scales one should specify the astronomical constructions and definitions of constants to make them consistent with general relativity (GRT). Such an approach is developed with the aid of the existing relativisting hierarchy of relativistic reference systems and time scales.

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