306,353 research outputs found
Non-orientable surface-plus-one-relation groups
No full textRecently Dicks–Linnell determined the L2-Betti numbers of the orientable surface-plus-one-relation groups, and their arguments involved some results that were obtained topologically by Hempel and Howie. Using algebraic arguments, we now extend all these results of Hempel and Howie to a larger class of two-relator groups, and we then apply the extended results to determine the L2-Betti numbers of the non-orientable surface-plus-one-relation group
On the local-indicability cohen–lyndon theorem
No full textFor a group H and a subset X of H, we let HX denote the set {hxh?1 | h ? H, x ? X}, and when X is a free-generating set of H, we say that the set HX is a Whitehead subset of H. For a group F and an element r of F, we say that r is Cohen–Lyndon aspherical in F if F{r} is a Whitehead subset of the subgroup of F that is generated by F{r}. In 1963, Cohen and Lyndon (D. E. Cohen and R. C. Lyndon, Free bases for normal subgroups of free groups, Trans. Amer. Math. Soc. 108 (1963), 526–537) independently showed that in each free group each non-trivial element is Cohen–Lyndon aspherical. Their proof used the celebrated induction method devised by Magnus in 1930 to study one-relator groups. In 1987, Edjvet and Howie (M. Edjvet and J. Howie, A Cohen–Lyndon theorem for free products of locally indicable groups, J. Pure Appl. Algebra 45 (1987), 41–44) showed that if A and B are locally indicable groups, then each cyclically reduced element of A*B that does not lie in A ? B is Cohen–Lyndon aspherical in A*B. Their proof used the original Cohen–Lyndon theorem. Using Bass–Serre theory, the original Cohen–Lyndon theorem and the Edjvet–Howie theorem, one can deduce the local-indicability Cohen–Lyndon theorem: if F is a locally indicable group and T is an F-tree with trivial edge stabilisers, then each element of F that fixes no vertex of T is Cohen–Lyndon aspherical in F. Conversely, by Bass–Serre theory, the original Cohen–Lyndon theorem and the Edjvet–Howie theorem are immediate consequences of the local-indicability Cohen–Lyndon theorem. In this paper we give a detailed review of a Bass–Serre theoretical form of Howie induction and arrange the arguments of Edjvet and Howie into a Howie-inductive proof of the local-indicability Cohen–Lyndon theorem that uses neither Magnus induction nor the original Cohen–Lyndon theorem. We conclude with a review of some standard applications of Cohen–Lyndon asphericit
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The economic and social status of Romano-British rural villas in southern England
No full textThe nature of rural settlement patterns and the economy during the Roman occupation of Britain from the Claudian invasion of AD 43 to the end of the fourth century in Hampshire and West Sussex formed the focus of this research.The objective is to define a method of measuring the attributes of Romano-British ceramic assemblages that can be linked to the socio-economic status of the original owners and their villas. It is the hypothesis of this study that domestic ceramic vessels can be used as a reliable indicator of social status. A tenet of this hypothesis is that the higher social and economically wealthy Romano British villa owners would be in possession of greater amounts of ceramic fine table wares. The pottery assemblages and the architectural features of twenty villas in West Sussex and Hampshire were analysed in order to test this hypothesis. The quantities of fine wares were measured by Estimated Vessel Equivalents (EVEs) and the Romanised architectural features present were quantified by their presence.The economics of the Roman Empire was integrated with wealth and power which in itself was reflected in the fashions of the material culture together with the aspirations to acquire status. Social mobility during the Rome Empire relied on wealth and the consequent display of that wealth. The way a person could demonstrate a change in status was to acquire and display higher quality material culture. This can be seen to be demonstrated in the display of Romanised architectural features present in Romano-British villas coupled with the evidence of high value ceramic fine wares present in the cultural artefacts. This demonstration of wealth can be seen as representing the status of an individual within society and by comparison the fewer high value status symbols would indicate a lower status or class of an individual.The differences in the quantity of these ceramic fine wares obtained by the villa owners can, therefore, be seen as an indicator and a measure of their relative social status. It is this theory that is the basis for the development of the methodology and the creation of a testable model
Student sermon: Dicks, Willie E., Jr.
No full textInterdenominational Theological Center student Willie E. Dicks Jr. delivers two sermons titled Recipe for Meaningful Use of Our Time and Considering Proper Self Discipline for Preaching Professionals. In the sermons, he discusses the role and responsibility of the preacher.The Atlanta University Center Robert W. Woodruff Library acknowledges the generous support of the National Endowment for Humanities - Humanities Collections and Reference Resources Implementation Project Grant in supporting the processing and digitization of a number of its major archival collections as part of the project: Spreading the Word: Expanding Access to African American Religious Archival Collections at the Atlanta University Center Robert W. Woodruff Library.</em
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Presentations for subgroups of Artin groups
No full textRecently, M. Bestvina and N. Brady have exhibited groups that are of type FP but not finitely presented. We give explicit presentations for groups of the type considered by Bestvina-Brady. This leads to algebraic proofs of some of their results
Female Dicks. Il gender e il genere nella serialità letteraria bolognese
No full textIn honor of Luigi Bernardi ten years after his death, this essay explores one of the most important of the author-editor’s areas of research, crime fiction. Where the rich and recent scholarship on the subject has favored a more transmedial approach, I here focus on the literary text, specifically three series of novels set in and around Bologna with female detectives: the series by Carlo Lucarelli with protagonist police inspector Grazia Negro, the series by Grazia Verasani featuring the private detective Giorgia Cantini, and two recent novels in a projected trilogy by Lorella Marini whose protagonist is Commissaria Barbara Larsen Givoni. From these serial novels I distill a triptych of ‘female dicks’: the Deferential, the Disquieting, and the Avenger, each of whom responds differently to the exigencies of the patriarchal system in which they operate, each of whose series illustrate greater and lesser degrees of adherence to generic conventions of the noir, representing the intersection of gender e genre.In omaggio a Luigi Bernardi a dieci anni dalla sua scomparsa, il presente saggio esplora uno dei campi più importanti nell’opera dell’autore-editore, la narrativa noir. Laddove le ricche recenti ricerche hanno adoperato un approccio transmediale, io invece mi concentro sul testo letterario, in particolare su tre serie di romanzi ubicati a Bologna e che hanno per protagonista una donna detective: la serie di Carlo Lucarelli con protagonista l’ispettrice Grazia Negro, la serie di romanzi di Grazia Verasani con protagonista l’investigatrice privata Giorgia Cantini, e due romanzi nella trilogia, in via di completamento, di Lorella Marini la cui protagonista è la commissaria Barbara Larsen Givoni. Dai romanzi seriali distillo un trittico di ‘female dicks’: la Deferente, la Scomoda, e la Vendicatrice, le cui narrative aderiscono in modi diversi alle convenzioni del noir, rappresentando l’intersezione di gender e genere
Author, publisher and bookseller : a tripartite synergy in Nigerian book industry
No full textThis work is about the roles of Author, Publisher and Bookseller in Book development in
Nigeria. The paper started by delving into the history of Book Publishing in Nigeria after
which it proceeded by defining who an author, a publisher, and a bookseller is and
expatiated on the indispensable roles of these key actors in Nigerian Book Industry and in
the emerging Information Society. Furthermore, the various constraints to book
development were identified while the paper advised on how the Book Industry can be
further promoted in Nigeria. However, the paper concluded and made recommendations
on how the Book sector can help in enhancing scholarship in the country
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