Vermistella arctica n. sp. Nominates the Genus Vermistella as a Candidate for Taxon with Bipolar Distribution

2015 ◽  
Vol 63 (2) ◽  
pp. 210-219 ◽  
Author(s):  
Tomáš Tyml ◽  
Martin Kostka ◽  
Oleg Ditrich ◽  
Iva Dyková
Keyword(s):  
Bipolar Distribution

scholarly journals Resolving the puzzle of type IIP SN 2016X

2019 ◽  
Vol 490 (2) ◽  
pp. 2042-2049 ◽  
Author(s):  
V P Utrobin ◽  
N N Chugai
Keyword(s):  
Kinetic Energy ◽  
Light Curve ◽  
Line Profile ◽  
Massive Star ◽  
Hydrodynamic Modelling ◽  
Thick Disc ◽  
Bipolar Distribution ◽  
Dust Absorption

ABSTRACT The enigmatic type IIP SN 2016X demonstrates the unprecedented asphericity in the nebular Hα line profile, the absence of nebular [O i] emission, and the unusual occultation effect due to the internal dust. The hydrodynamic modelling of the bolometric light curve and expansion velocities suggests that the event is an outcome of the massive star explosion that ejected 28 M$\odot$ with the kinetic energy of 1.7 × 1051 erg and 0.03 M$\odot$ of radioactive 56Ni. We recover the bipolar distribution of 56Ni from the Hα profile via the simulation of the emissivity produced by non-spherical 56Ni ejecta. The conspicuous effect of the dust absorption in the Hα profile rules out the occultation by the dusty sphere or dusty thick disc, but turns out consistent with the thin dusty disc-like structure in the plane perpendicular to the bipolar axis. We speculate that the absence of the nebular [O i] emission might originate from the significant cooling of the oxygen-rich matter mediated by CO and SiO molecules.

scholarly journals Bipolar distribution of the cyst-forming dinoflagellate Polarella glacialis

Polar Biology ◽  
2003 ◽  
Vol 26 (3) ◽  
pp. 186-194 ◽  
Author(s):  
M. Montresor ◽  
C. Lovejoy ◽  
L. Orsini ◽  
G. Procaccini ◽  
S. Roy
Keyword(s):  
Bipolar Distribution

The rare species Synura lapponica (Synurophyceae) new to the Czech Republic, local vs. global diversity in colonial synurophytes

Biologia ◽  
2009 ◽  
Vol 64 (6) ◽  
Author(s):  
Yvonne Němcová ◽  
Martina Pichrtová
Keyword(s):  
Czech Republic ◽  
Rare Species ◽  
Environmental Variables ◽  
Considerable Increase ◽  
Sampling Effort ◽  
Seasonal Fluctuations ◽  
The Czech Republic ◽  
Ecological Requirements ◽  
Bipolar Distribution ◽  
First Time

AbstractSynura lapponica Skuja, a freshwater colonial flagellate (Synurophyceae, Stramenopila), has been reported for the first time in the Czech Republic. This study evaluates the ecological requirements of the species, and includes a survey of the literature. Although S. lapponica has been reported thus far only in the Northern Hemisphere, the probability of its bipolar distribution is relatively high (22%). Distribution is probably ecologically determined, water temperature (correlated with latitude or seasonal fluctuations), and lower pH seem to be the primary environmental variables. A local vs. global ratio reflects, to a certain extent, the degree of sampling effort expended in the studied area, but a considerable increase in the number of revealed taxa was apparent when the area was expanded.

scholarly journals Marine bacteria exhibit a bipolar distribution

2013 ◽  
Vol 110 (6) ◽  
pp. 2342-2347 ◽  
Author(s):  
W. J. Sul ◽  
T. A. Oliver ◽  
H. W. Ducklow ◽  
L. A. Amaral-Zettler ◽  
M. L. Sogin
Keyword(s):  
Marine Bacteria ◽  
Bipolar Distribution

The Stochastic Process of Alliance Formation Behavior

1978 ◽  
Vol 72 (4) ◽  
pp. 1288-1303 ◽  
Author(s):  
Richard P. Y. Li ◽  
William R. Thompson
Keyword(s):  
Stochastic Process ◽  
International Relations ◽  
Balance Of Power ◽  
Serial Dependence ◽  
Alliance Formation ◽  
Continuous Analogue ◽  
Formation Behavior ◽  
Bipolar Distribution ◽  
Modeling Strategy ◽  
Analyze Data

This article attempts to examine alliance formation behavior as a stochastic process amenable to systems interpretation. We test two hypotheses linking the systems characteristics of bipolar distribution/tightly knit bloc structure to serial dependence and stability of alliance formation behavior and multipolar distribution/loosely knit bloc structure to randomness and process instability.For testing these hypotheses, we have introduced a modeling strategy whereby identification of serial dependence and parameter estimation are accomplished by means of stochastic difference equations and time series autocorrelation and partial autocorrelation functions, and systems interpretation is facilitated by employing its continuous analogue in differential equation form.We analyze data on three sets of observations corresponding to three distinct periods of international relations: 1815–1914, 1919–1939, 1945–1965. The results do confirm the proposed hypotheses revealing randomness and instability of alliance formation behavior in the multipolar/loosely knit periods of 1815–1914 and 1919–1939 and serial dependence and stability in the bipolar/tightly knit 1945–1965 period. Finally, we consider the implications of these results for the earlier findings, the balance of power model, and the probability of war.

Origins of North American Biogeographic Affinities

1999 ◽  
Author(s):  
Alan Graham
Keyword(s):  
South Carolina ◽  
North American ◽  
New World ◽  
Plant Distribution ◽  
Land Bridge ◽  
The North ◽  
The Earth ◽  
Bipolar Distribution ◽  
Imaginative Thinking ◽  
George Gaylord Simpson

An aspect of plant distribution that has intrigued biogeographers for over 200 years is the occurrence of similar biotas in widely separated regions. The North American flora has affinities with several such areas: the Mediterranean, the dry regions of South America, eastern Asia, and eastern Mexico. The origin of some patterns is relatively clear, while for others hypotheses are just now being formulated. During times when the dogma of permanence of continents and ocean basins held sway, explanations for these disjunctions required imaginative thinking that often bordered on the bizarre. The pendulum or schwingpolen hypothesis was offered to explain the perceived bipolar distribution of several taxa (Gnetum, Magnolia, Pinus section Taeda; Simroth, 1914). By this view, the Earth swings in space like a pendulum, creating regular fluctuations in environments and often causing the symmetrical placement of taxa at two points on opposite sides of the Earth. Other disjunctions were explained by casually placing geophysically impossible land bridges at any point in time between any two sites where the presence of similar communities seemed to call for land connections (see review in Simpson, 1943). The presence of teeth of Hipparion, an ungulate related to the horse, in Europe and South Carolina-Florida prompted French geologist Leonce Joleaud to propose a land bridge extending from Florida through the Antilles to North Africa and Spain. Subsequently, to accommodate eight new passengers, it was broadened to encompass the entire region from Maryland and Brazil across to France and Morocco and its life was prolonged to include virtually all of the Tertiary. With the later discovery that there were periodicities in similarity between Old World and New World Cenozoic faunas, the continents were envisioned as moving back and forth like an accordion. George Gaylord Simpson, who favored the North Atlantic land bridge to connect North America and Europe, was beside himself with these theories and characterized Joelaud’s as “the climax of all drift theories.” The bridge became well established in the literature even though it never existed in the Atlantic Ocean (Marvin, 1973). Udvardy (1969) plotted all the Cretaceous and Tertiary land bridges postulated for the South Pacific up to 1913.

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