A controllable model of a random multiplicative process for the entire distribution of population

2008 ◽  
Vol 387 (5-6) ◽  
pp. 1345-1351 ◽  
Author(s):  
Shinji Tomita ◽  
Yukio Hayashi
Keyword(s):  
Multiplicative Process ◽  
Random Multiplicative Process ◽  
Entire Distribution

FROM LOGNORMAL DISTRIBUTION TO POWER LAW: A NEW CLASSIFICATION OF THE SIZE DISTRIBUTIONS

2006 ◽  
Vol 17 (10) ◽  
pp. 1429-1436 ◽  
Author(s):  
LUCIEN BENGUIGUI ◽  
EFRAT BLUMENFELD-LIEBERTHAL
Keyword(s):  
Normal Distribution ◽  
Power Law ◽  
Lognormal Distribution ◽  
Size Distributions ◽  
New Classification ◽  
Multiplicative Process ◽  
Random Multiplicative Process ◽  
Log Normal ◽  
Log Normal Distribution

We propose a new classification of the size distributions of entities based on an exponent α defined from the shape of the log–log Rank Size plot. From an inspection of a large number of cases in different fields, one finds three possibilities: α = 1 giving a power law, α > 1 (parabola like curve) and 0 < α < 1 (analogous to a log normal distribution). A fourth possibility that can be defined when α < 0 was never observed. We present a modified version of models based on a random multiplicative process and an introduction of new entities during the growth. We recover all three kinds of distributions and show that the type of a distribution is conditioned by the rate of the introduction of new entities.

scholarly journals Stand out from the Crowd: Small-Scale Genetic Structuring in the Endemic Sicilian Pond Turtle

Diversity ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 343
Author(s):  
Luca Vecchioni ◽  
Federico Marrone ◽  
Marco Arculeo ◽  
Uwe Fritz ◽  
Melita Vamberger
Keyword(s):  
Genetic Diversity ◽  
Microsatellite Loci ◽  
Small Scale ◽  
Moderate Degree ◽  
Geographical Pattern ◽  
Genetic Structuring ◽  
Pond Turtle ◽  
Emys Trinacris ◽  
Polymorphic Microsatellite ◽  
Entire Distribution

The geographical pattern of genetic diversity was investigated in the endemic Sicilian pond turtle Emys trinacris across its entire distribution range, using 16 microsatellite loci. Overall, 245 specimens of E. trinacris were studied, showing high polymorphic microsatellite loci, with allele numbers ranging from 7 to 30. STRUCTURE and GENELAND analyses showed a noteworthy, geographically based structuring of the studied populations in five well-characterized clusters, supported by a moderate degree of genetic diversity (FST values between 0.075 and 0.160). Possible explanations for the genetic fragmentation observed are provided, where both natural and human-mediated habitat fragmentation of the Sicilian wetlands played a major role in this process. Finally, some conservation and management suggestions aimed at preventing the loss of genetic variability of the species are briefly reported, stressing the importance of considering the five detected clusters as independent Management Units.

scholarly journals Sporophytes of the rare liverwort Cephalozia macounii

2013 ◽  
Vol 58 (2) ◽  
pp. 491-494 ◽  
Author(s):  
Sanna Laaka-Lindberg ◽  
Kimmo Syrjänen
Keyword(s):  
Northern Hemisphere ◽  
Critically Endangered ◽  
Reproductive Capacity ◽  
Distribution Area ◽  
Habitats Directive ◽  
Eu Habitats Directive ◽  
The Eu ◽  
Entire Distribution

Abstract The dioicous epixylic liverwort Cephalozia macounii (Aust.) Aust. is rare over its entire distribution area in the Northern Hemisphere. It is protected under the EU Habitats Directive and classified as critically endangered in Finland and Sweden. One reason cited for its rareness and the declining trend in its distribution its poor reproductive capacity. It does not produce asexual gemmae, which in general is common among liverworts. Although female plants with perianths are quite common, the male plants of the species have rarely been seen and sporophytes have not been described until now. In this paper we describe and illustrate the sporophytes of C. macounii on the basis of an old specimen collected in Southern Finland in the 1800s.

scholarly journals When is a Verb not a Verb?

Nordlyd ◽  
10.7557/12.11 ◽  
2004 ◽  
Vol 31 (2) ◽  
Author(s):  
Carson Schütze
Keyword(s):  
Central Issue ◽  
High Position ◽  
Vp Ellipsis ◽  
Categorial Status ◽  
Entire Distribution

Changes are proposed to the categorial status traditionally accorded to Aux-related and verbal elements in the clause, and the new taxonomy is applied in implementing the old insight that <em>be</em> should be analyzed as the default, semantically empty verb. The central issue is when a verb-like element does (not) count as categorially a V for distributional purposes. The major proposals are: 1) to remove <em>be</em> and <em>have</em> from the category Aux and treat them as Vs; 2) to separate out participles from genuine tensed and bare verbs; 3) to group <em>do</em> with modals, rather than with <em>have</em> and <em>be</em>, into a category Mood that also includes a null indicative morpheme. This scheme is used to account for the entire distribution of the forms of <em>be</em> just by treating it as V with no properties. <em>Be</em> fulfills two requirements that cannot always be met by contentful verbs: first, it satisfies the syntactico-semantic need for Tense to c-command a clause-mate V (the “V Requirement”); second, it satisfies the morphosyntactic need for participial affixes ( <em>-ing, -en</em>) to have hosts. It is shown how the former requirement derives the exceptionally high position of finite <em>be</em> by base-generating it above negation etc., rather than raising it across. VP-ellipsis data provide independent support for this treatment. Finally, some tentative suggestions are offered for how the V Requirement might be derived from deeper principles, while still allowing for the fact that it is apparently not fully enforced in languages with null copulas.

Localities and sites of the neglected umbellifer Physospermum verticillatum (Apiaceae) on Mt. Slavnik in southwestern Slovenia / Nahajališča in rastišča prezrte kobulnice Physospermum verticillatum (Apiaceae) na Slavniku v jugozahodni Sloveniji

2021 ◽  
Vol 62 (1) ◽  
pp. 11-31
Author(s):  
Igor Dakskobler ◽  
Valerija Babij
Keyword(s):  
Key Words ◽  
Red List ◽  
Distribution Area ◽  
Forest Edges ◽  
Fringe Communities ◽  
Sw Slovenia ◽  
Entire Distribution

On the shady (northern) slopes of Mt. Slavnik (Slavnik mountains, Čičarija, SW Slovenia) we identified Physospermum verticillatum (Apiaceae), a species whose northernmost known sites in its entire distribution area had until then been in the Croatian part of Čičarija near the border with Slovenia (Žbevnica near Dane). It occurs mainly in beech stands from the association Seslerio autumnalis-Fagetum, frequently in smaller gaps, on forest edges and road banks, where it occurs in fringe communities (Calamintho grandiflorae-Physospermetum verticillatinom. prov.), at elevations spanning 800 m to 1000 m. The plants are vital, most of them develop flowers and fruit. Although it is justified to assume that it may occur elsewhere in the Slovenian part of Čičarija, we propose it be classified in the Red List as rare. Key words: flora, Physospermum verticillatum, vegetation, Seslerio autumnalis-Fagetum, Čičarija, Istria, Slovenia   Izvleček Na osojnih (severnih) pobočjih Slavnika (Slavniško hribovje, Čičarija, jugozahodna Slovenija) smo našli vrsto Physospermum verticillatum(Apiaceae), ki je do zdaj imela najbolj severna znana nahajališča v svojem celotnem arealu v hrvaškem delu Čičarije blizu meje s Slovenijo (Žbevnica pri Danah). Raste predvsem v bukovih sestojih iz asociacije Seslerio autumnalis-Fagetum, pogosto v manjših vrzelih, tudi na gozdnem robu in cestni brežini, tam v robnih združbah (Calamintho grandiflorae-Physospermetum verticillatinom. prov.), na nadmorski višini od 800 m do 1000 m. Rastline so vitalne, večinoma cvetijo in plodijo. Kljub temu in upravičeni domnevi, da v slovenskem delu Čičarije lahko raste tudi drugod, jo predlagamo kot redko za uvrstitev na rdeči seznam. Ključne besede: flora, Physospermum verticillatum, vegetacija, Seslerio autumnalis-Fagetum, Čičarija, Istra, Slovenija

The potential impact of mining on population genetic variation in the Banded Ironstone Formation endemic Tetratheca erubescens (Elaeocarpaceae)

2019 ◽  
Vol 67 (3) ◽  
pp. 172 ◽  
Author(s):  
Siegfried L. Krauss ◽  
Janet M. Anthony
Keyword(s):  
Genetic Variation ◽  
Population Genetic ◽  
Allelic Variation ◽  
Continuous Distribution ◽  
Genetic Structuring ◽  
Expected Heterozygosity ◽  
Spatial Structuring ◽  
Genetic Clusters ◽  
Population Genetic Variation ◽  
Entire Distribution

Tetratheca erubescens is a narrowly endemic species including ~6300 plants restricted to a 2-km2 distribution on the south Koolyanobbing Range Banded Ironstone Formation (BIF) in Western Australia. A key objective of the present study was to characterise population genetic variation, and its spatial structuring across the entire distribution of T. erubescens, to enable a quantification of genetic variation that may be affected by proposed mining of the BIF. In total, 436 plants (~30 at each of 14 sites) from across the entire distribution were sampled, genotyped and scored for allelic variation at 11 polymorphic microsatellite loci. Fifty-nine alleles were detected (mean alleles per locus=5.36, range 2–10), and observed heterozygosity was low to moderate and typically lower than expected heterozygosity across all loci (mean observed heterozygosity (Ho)=0.41, mean expected heterozygosity (He)=0.48). Given the restricted distribution of T. erubescens, overall genetic structuring was surprisingly strong (overall FST=0.098). A range-wide spatial autocorrelation analysis indicated a significant positive genetic correlation at distances up to 450m, largely corresponding to the scale of more-or-less continuous distribution within each of two geographic clusters. In support, a STRUCTURE analysis identified an optimal number of genetic clusters as K=2, with assignment of individuals to one of two genetic clusters corresponding with the main geographic clusters. The genetic impact of proposed mining on T. erubescens was assessed on the basis of identifying plants within the proposed mine footprint (all plants from 4 of 14 sites). Repeating analyses of genetic variation after removal of these samples, and comparing to the complete dataset adjusted for sample size, resulted in the loss of one (very rare: overall frequency=0.001) allele (i.e. 58 of 59 alleles (98.3%) were recovered). All other parameters of genetic variation (mean Na, Ne, I, Ho, He, F) were unaffected. Consequently, although up to 22% of all plants fall within the mine footprint and, therefore, may be lost, &lt;2% of alleles detected will be lost, and other genetic parameters remained unaffected. Although these results suggest that the proposed mining will result in a negligible impact on the assessed genetic variation and its spatial structuring in T. erubescens, further research on impacts to, and management of, quantitative genetic variation and key population genetic processes is required.

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