Magnifying Elements in a Semigroup of Transformations with Restricted Range

2018 ◽  
Vol 30 (1) ◽  
pp. 54-58
Author(s):  
Ronnason Chinram ◽  
Samruam Baupradist
Mathematics ◽  
2018 ◽  
Vol 6 (8) ◽  
pp. 134
Author(s):  
Chollawat Pookpienlert ◽  
Preeyanuch Honyam ◽  
Jintana Sanwong

Let T(X,Y) be the semigroup consisting of all total transformations from X into a fixed nonempty subset Y of X. For an equivalence relation ρ on X, let ρ^ be the restriction of ρ on Y, R a cross-section of Y/ρ^ and define T(X,Y,ρ,R) to be the set of all total transformations α from X into Y such that α preserves both ρ (if (a,b)∈ρ, then (aα,bα)∈ρ) and R (if r∈R, then rα∈R). T(X,Y,ρ,R) is then a subsemigroup of T(X,Y). In this paper, we give descriptions of Green’s relations on T(X,Y,ρ,R), and these results extend the results on T(X,Y) and T(X,ρ,R) when taking ρ to be the identity relation and Y=X, respectively.


Author(s):  
Jintana Sanwong ◽  
Worachead Sommanee

LetT(X)be the full transformation semigroup on the setXand letT(X,Y)={α∈T(X):Xα⊆Y}. ThenT(X,Y)is a sub-semigroup ofT(X)determined by a nonempty subsetYofX. In this paper, we give a necessary and sufficient condition forT(X,Y)to be regular. In the case thatT(X,Y)is not regular, the largest regular sub-semigroup is obtained and this sub-semigroup is shown to determine the Green's relations onT(X,Y). Also, a class of maximal inverse sub-semigroups ofT(X,Y)is obtained.


2019 ◽  
Vol 46 (1) ◽  
pp. 63-74
Author(s):  
Stefano Mattioli

The rediscovery of the original, unedited Latin manuscript of Georg Wilhelm Steller's “De bestiis marinis” (“On marine mammals”), first published in 1751, calls for a new translation into English. The main part of the treatise contains detailed descriptions of four marine mammals, but the introduction is devoted to more general issues, including innovative speculation on morphology, ecology and biogeography, anticipating arguments and concepts of modern biology. Steller noted early that climate and food have a direct influence on body size, pelage and functional traits of mammals, potentially affecting reversible changes (phenotypic plasticity). Feeding and other behavioural habits have an impact on the geographical distribution of mammals. Species with a broad diet tend to have a wide distribution, whereas animals with a narrow diet more likely have only a restricted range. According to Steller, both sea and land then still concealed countless animals unknown to science.


2015 ◽  
Vol 44 (1) ◽  
pp. 253-264 ◽  
Author(s):  
Vítor H. Fernandes ◽  
Preeyanuch Honyam ◽  
Teresa M. Quinteiro ◽  
Boorapa Singha
Keyword(s):  

2013 ◽  
Vol 91 (2) ◽  
pp. 301-308 ◽  
Author(s):  
José Luis Guil-Guerrero ◽  
Francisco Gómez-Mercado ◽  
Rebeca Pilar Ramos-Bueno ◽  
Miguel Ángel Rincón-Cervera ◽  
Elena Venegas-Venegas

1981 ◽  
Vol 8 (1) ◽  
pp. 203 ◽  
Author(s):  
AA Burbidge

Western swamp tortoise (Pseudemydura umbrina) was rediscovered in Western Australia in 1954. It is a relict species of a monotypic genus, of very restricted range and specialized habitat. Population was estimated to be 13 to 45 and decreasing at 1 of its 2 native reserves and to be 10 to 45 and static at the other reserve. It does not use permanent water, but lives and feeds in ephemeral winter swamps and spends the other 6 to 9 months of the year in refuges in leaf litter, under fallen branches or in holes in the ground, in contact with the soil. The tortoise is carnivorous and in the wild takes only live aquatic organisms. Captive adults will not take meat until they have starved for many months. Stomach of 1 female (Edward, pers. commun.) had aquatic crustaceans, chiefly Eulimnadia sp., with insects and insect larvae, mainly Coleoptera and Diptera. Study of faeces confirmed that observation had shown that small tadpoles and an aquatic earthworm (Eodrilus cornigravei) were eaten also. Reproduction, growth, activity relative to body and water temperature, and desiccation rate, were noted. One adult female tortoise was eaten by a fox. Foxes and bandicoots (Isoodon obesulus) eat eggs of other tortoises and would eat those of P. umbrina. Hatchlings may be eaten by large wading birds such as straw-necked ibis (Threskiornis spinicollis) and white-faced heron (Notophoyx novaehollandiae).


Oryx ◽  
1998 ◽  
Vol 32 (1) ◽  
pp. 59-67 ◽  
Author(s):  
R. J. Timmins ◽  
T. D. Evans ◽  
Khamkhoun Khounboline ◽  
Chainoi Sisomphone

The large-antlered, or giant, muntjac Megamuntiacus vuquangensis wasdescribed from Vietnam in 1994 and found concurrently in the Annamite Mountains and nearby hill ranges of central and southern Laos. The northerly and southerly range limits are still unknown. It may occupy a wide range of habitats and is found sympatrically with the common muntjac Muntiacus muntjak. Another muntjac species, the taxonomic affinity of which is as yet undetermined, was recently discovered to occur within its range. The large-antlered muntjac is probably not threatened with extinction in the near future, but in view of its restricted range and threats from habitat degradation and hunting, it should be classified as Vulnerable in the Red Data Book. Its future in Laos is largely dependent on the recently created protected-areas system to maintain large tracts of habitat and reduce hunting pressure.


PLoS ONE ◽  
2013 ◽  
Vol 8 (9) ◽  
pp. e74148 ◽  
Author(s):  
Ricardo Faustino de Lima ◽  
Fábio Olmos ◽  
Martin Dallimer ◽  
Philip W. Atkinson ◽  
Jos Barlow

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