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4832. Basic subgroups in abelian group rings
- Creator:
- Danchev, Peter Vassilev
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- basic and lower basic subgroups, units, and modular abelian group rings
- Language:
- English
- Description:
- Suppose $R$ is a commutative ring with identity of prime characteristic $p$ and $G$ is an arbitrary abelian $p$-group. In the present paper, a basic subgroup and a lower basic subgroup of the $p$-component $U_p(RG)$ and of the factor-group $U_p(RG)/G$ of the unit group $U(RG)$ in the modular group algebra $RG$ are established, in the case when $R$ is weakly perfect. Moreover, a lower basic subgroup and a basic subgroup of the normed $p$-component $S(RG)$ and of the quotient group $S(RG)/G_p$ are given when $R$ is perfect and $G$ is arbitrary whose $G/G_p$ is $p$-divisible. These results extend and generalize a result due to Nachev (1996) published in Houston J. Math., when the ring $R$ is perfect and $G$ is $p$-primary. Some other applications in this direction are also obtained for the direct factor problem and for a kind of an arbitrary basic subgroup.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
4833. Basic subgroups in commutative modular group rings
- Creator:
- Danchev, Peter V.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- perfect rings, Abelian p-groups, groups of normalized units, group rings, and basic subgroups
- Language:
- English
- Description:
- Let S(RG) be a normed Sylow p-subgroup in a group ring RG of an abelian group G with p-component Gp and a p-basic subgroup B over a commutative unitary ring R with prime characteristic p. The first central result is that 1 + I(RG; Bp) + I(R(p i )G; G) is basic in S(RG) and B[1 + I(RG; Bp) + I(R(p i )G; G)] is p-basic in V (RG), and [1 + I(RG; Bp) + I(R(p i )G; G)]Gp/Gp is basic in S(RG)/Gp and [1 + I(RG; Bp) + I(R(p i )G; G)]G/G is p-basic in V (RG)/G, provided in both cases G/Gp is p-divisible and R is such that its maximal perfect subring R p i has no nilpotents whenever i is natural. The second major result is that B(1 + I(RG; Bp)) is p-basic in V (RG) and (1 + I(RG; Bp))G/G is p-basic in V (RG)/G, provided G/Gp is p-divisible and R is perfect. In particular, under these circumstances, S(RG) and S(RG)/Gp are both starred or algebraically compact groups. The last results offer a new perspective on the long-standing classical conjecture which says that S(RG)/Gp is totally projective. The present facts improve the results concerning this topic due to Nachev (Houston J. Math., 1996) and others obtained by us in (C. R. Acad. Bulg. Sci., 1995) and (Czechoslovak Math. J., 2002).
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
4834. Basic subgroups in modular abelian group algebras
- Creator:
- Danchev, Peter
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- $p$-basic subgroups, normalized units, group algebras, and starred groups
- Language:
- English
- Description:
- Suppose ${F}$ is a perfect field of ${\mathop {\mathrm char}F=p\ne 0}$ and ${G}$ is an arbitrary abelian multiplicative group with a ${p}$-basic subgroup ${B}$ and ${p}$-component ${G_p}$. Let ${FG}$ be the group algebra with normed group of all units ${V(FG)}$ and its Sylow ${p}$-subgroup ${S(FG)}$, and let ${I_p(FG;B)}$ be the nilradical of the relative augmentation ideal ${I(FG;B)}$ of ${FG}$ with respect to ${B}$. The main results that motivate this article are that ${1+I_p(FG;B)}$ is basic in ${S(FG)}$, and ${B(1+I_p(FG;B))}$ is ${p}$-basic in ${V(FG)}$ provided ${G}$ is ${p}$-mixed. These achievements extend in some way a result of N. Nachev (1996) in Houston J. Math. when ${G}$ is $p$-primary. Thus the problem of obtaining a ($p$-)basic subgroup in ${FG}$ is completely resolved provided that the field $F$ is perfect. Moreover, it is shown that ${G_p(1+I_p(FG;B))/G_p}$ is basic in ${S(FG)/ G_p}$, and $G(1+I_p(FG; B))/G$ is basic in ${V(FG)/G}$ provided ${G}$ is ${p}$-mixed. As consequences, ${S(FG)}$ and ${S(FG)/G_p}$ are both starred or divisible groups. All of the listed assertions enlarge in a new aspect affirmations established by us in Czechoslovak Math. J. (2002), Math. Bohemica (2004) and Math. Slovaca (2005) as well.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
4835. Basic vocabulary on the Human Genome
- Publisher:
- Institut Universitari de Lingüística Aplicada, Universitat Pompeu Fabra
- Type:
- lexicalConceptualResource
- Language:
- Catalan, English, French, Galician, Italian, Portuguese, and Spanish
- Description:
- A vocabulary resulting from the cooperation of the groups of REALITER network that collects the basic terminology mostly used in texts about Genomics. It contains equivalents in English, Peninsular and Latinamerican Spanish, French, Italian, Galician, Portuguese and Catalan.
- Rights:
- Not specified
4836. Basilica of the Visitation of Virgin Mary in Frýdek =
- Creator:
- Pindur, David,
- Type:
- text and přehledy
- Subject:
- Architektura, kostely, památky církevní, místa poutní, kult mariánský, církevní architektura, hmotné památky, hřbitovy a poutní místa, and přehledná zpracování dějin českých zemí (chronologicky)
- Language:
- English and German
- Description:
- Přeloženo z češtiny and 1000 výt.
- Rights:
- unknown
4837. Básnické spisy
- Creator:
- Pavel Josef Šafařík and Jan Vilikovský
- Publisher:
- V generální komisi nakl. Melantrich and Nákladem Učené společnosti Šafaříkovy
- Format:
- print, text, regular print, and xxxvi, 467 s. : faksim. ; 25 cm
- Type:
- model:monograph and TEXT
- Subject:
- Slovenská literatura, 821.162.4-1, 821.162.4-2, (081.1), 25, and 821.162.4
- Language:
- Czech, English, German, and Latin
- Description:
- Pavel Josef Šafařík ; vydal Jan Vilikovský, 1000 výt., Obsahuje bibliografické odkazy a rejstřík, and Část. staročeský, anglický, německý a latinský text
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
4838. Basset Y., Novotný V., Miller S.E. & Kitching R.L. (eds): Arthropods of Tropical Forests: Spatio-temporal Dynamics and Resource Use in the Canopy
- Creator:
- Aiello, A.
- Type:
- article, model:article, and TEXT
- Language:
- English
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
4839. Bat community structure within riparian areas of northwestern Georgia, USA
- Creator:
- Johnson, Joshua B., Ford, W. Mark, Edwards, John W., and Menzel, Michael A.
- Type:
- article and TEXT
- Subject:
- Anabat, Eptesicus, Lasiurus, Myotis, nonmetric multidimensional scaling, Perimyotis, regression tree, and species richness
- Language:
- English
- Description:
- Although it is well known that bats commonly forage in riparian areas, which provide water resources and insect concentrations, the role that the physical structure of riparian areas plays in influencing local bat communities is less certain. In 2000–2002, we used acoustic monitoring to determine bat species presence at 338 riparian sites in northwestern Georgia, USA. We used a 2-dimensional nonmetric multidimensional scaling (NMDS) ordination to assess how separations among species were partially associated with riparian conditions. Our NMDS analysis found some degree of habitat partitioning among bat species occurring in northwestern Georgia and was dictated in part by riparian condition. Myotis grisescens and M. septentrionalis were associated with low-elevation lotic waterways, whereas M. lucifugus, Lasiurus borealis, and Eptesicus fuscus were associated with high-elevation lentic waterways with sparse canopy cover. However, riparian conditions had weak relations with NMDS axes, possibly resulting in coincidental associations in some cases. Regression tree analysis indicated that higher bat species richness was associated with apparently uncommon small, high-elevation waterways with sparse canopy cover as well as larger streams and rivers that had wetlands adjacent to them. Including high-elevation waterways with existing management recommendations for endangered M. grisescens foraging areas (large, low-elevation streams and rivers) will be the most effective conservation strategy to benefit the most bat species in northwestern Georgia and probably elsewhere in the southern Appalachians.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/
4840. Bat predation by the barn owl in a hibernation site of bats
- Creator:
- Sommer, Robert S., Niederle, Marlene, Labes, Ralph, and Zoller, Hinrich
- Type:
- article and TEXT
- Subject:
- feeding ecology, food preference, pellet analysis, Myotis, and Chiroptera
- Language:
- English
- Description:
- Bats appear regularly among the mammalian prey species of the barn owl. However, from numerous studies of owl pellets, bats are rarely represented in the prey of the barn owl and usually make up less than 1% of the prey individuals. Prey remains of the barn owl from the fortress Dömitz, south-east of Mecklenburg-Western Pomerania (Germany) were collected and analysed. A total of 2931 identifiable fragments from at least 1100 vertebrate individuals were discovered and identified. The analysis of the pellets over a four year period shows that, aside from the typical spectrum of mammalian prey (voles 34.9%, shrews 24.6 % and mice 13.8%), a relatively large proportion of prey individuals (26.6 %) were bats. From the pellet sample from 2002, Natterer’s bat Myotis nattereri were clearly the dominant prey with 79 individuals (30.2 %) followed by the common vole Microtus arvalis with 74 individuals (28.2 %). This high frequency of bats from the 2002 sample led to a total percentage of bats of almost 39 % and bats were clearly dominant over other potential prey groups. The frequency of bats in all samples is much higher than in all other known studies of barn owl pellet samples in a comparable volume. Our results show that Tyto alba is an opportunistic but no selective hunter of bats.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/