A group G is called a barely transitive group if it acts transitively and faithfully on an infinite set and every orbit of every proper subgroup is finite. A subgroup H of a group G is called a permutable subgroup, if H commutes with every subgroup of G. We showed that if an infinitely generated barely transitive group G has a permutable point stabilizer, then G is locally finite. We proved that if a barely transitive group G has an abelian point stabilizer H, then G is isomorphic to one of the followings: (i) G is a metabelian locally finite p-group, (ii) G is a finitely generated quasi-finite group (in particular H is finite), (iii) G is a finitely generated group with a maximal normal subgroup N where N is a locally finite metabelian group. In particular, G=N is a quasi-finite simple group. In all of the three cases, G is periodic.

Borderline personality disorder (BPD) is a complex psychiatric condition whose severity is compounded by the heterogeneous psychological functioning of those who suffer from the disorder. This heterogeneity has made the identification of a unified treatment strategy difficult and attempts to resolve this variation within the disorder by investigating subtypes of BPD have been made. However, the clinical utility of this approach has not been examined. The major object of this research project was to investigate the presence of subtypes of BPD and to examine whether treatment effectiveness varied as a function of subtype. Data from 61, predominantly female, participants with BPD were entered into a cluster analysis. Using variables that are central to cognitive behavioural models of BPD and have been shown to be heterogeneously distributed in previous BPD samples, two subgroups were identified and defined on the basis of whether participants attributed the causes o f negative events as being themselves or other people. Consistent with hypotheses, the subgroup with a tendency to blame others for negative events showed far lower levels of change between admission and discharge than the subgroup who blamed themselves for negative events, on both measures of statistical and clinical significance. Alternate means of identifying participants who optimally responded to the intervention were explored and a cluster analysis identified two groups of participants that were separated on the basis of whether they had shown clinically significant change on a range of variables. It was found that data from admission to the program could successfully predict which participants would belong in the optimal or mixed response groups upon discharge. Taken together, the findings of this research project suggest that not only can theoretically valid subgroups of BPD be identified, but that they have clinical utility in understanding participants' response to intervention. Further, the findi ngs suggest that profiles of clinical change can be identified and predicted. The findings of this research project are discussed with respect to their methodological limitations, suggestions for future research, and their implications for both theory and practice.

abstract: Differentiating bilingual children with primary language impairment (PLI) from those with typical development in the process of learning a second language has been a challenge. Studies have focused on improving the diagnostic accuracy of language measures for bilinguals. However, researchers are faced with two main challenges when estimating the diagnostic accuracy of new measures: (a) using an a priori diagnosis of children (children with and without PLI), as a reference may introduce error given there is no gold standard for the a priori classification; and (b) classifying children into only two groups may be another source of error given evidence that there may be more than two language ability groups with different strengths and weaknesses or, alternatively, a single group characterized by a continuum of language performance. The current study tested for the number of distinct language ability groups and their characteristics in predominately Spanish-speaking children in the U.S. without using an a priori classification as a reference. In addition, the study examined to what extent the latent groups differed on each measure, and the stability of language ability groups across three assessment methods in Spanish (standardized tests, language sample analyses, and comprehensive assessment), taking in to account English and non-verbal cognitive skills. The study included 431 bilingual children attending English-only education. Three latent profile analyses were conducted, one for each method of assessment. Results suggested more than two distinct language ability groups in the population with the method of assessment influencing the number and characteristics of the groups. Specifically, four groups were estimated based on the comprehensive assessment, and three based on standardized assessment or language sample analysis in Spanish. The stability of the groups was high on average, particularly between the comprehensive assessment and the standardized measures. Results indicate that an a priori classification of children into two groups, those with and without PLI, could lead to misclassification, depending on the measures used. / Dissertation/Thesis / Ph.D. Speech and Hearing Science 2012

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Esta dissertaÃÃo à baseado no artigo "Covering groups with subgroups" de R. A. Bryce, V. Fedri e L. Serena, onde caracterizam os grupos que admitem uma cobertura irredundante por cinco subgrupos maximais com interseÃÃo livre de nÃcleo. AlÃm disso, a intersecÃÃo de uma cobertura irredundante por n subgrupos à conhecido por ter Ãndice delimitada por uma funÃÃo de n, embora em geral, a limitaÃÃo precisa nÃo à conhecida. Aqui nÃs confirmamos um crÃdito de Tomkinson que a limitaÃÃo correta à 16 quando n à 5. / This dissertation is based on the article "Covering groups with subgroups" of R. A. Bryce, V. Fedra and L. Serena, which characterize groups that admit a cover by five maximal irredundant subgroups with free core intersection. The intersection of an irredundant cover by n subgroups is known to have index bounded by a function of n, though in general the precise bound is not known. Here we confirm a claim of Tomkinson that the correct bound is 16 when n is 5.

Theory and research suggest that at least two subgroups of individuals with psychopathicpersonality that can be differentiated based on their levels of anxiety. What we know so far ofthe distinction between these subgroups is based predominantly on relatively small samples ofmales in institutionalized populations. The present study is the first to use a large andrandomly selected sample of the general population to try to identify subgroups of individualswith psychopathic personality separately for males and females (n=2500; 52.6% females;M=22.15; SD=1.38). Latent profile analysis suggested a two-group solution; where bothsubgroups were high on psychopathic traits, but low respectively high on a measure ofanxiety. The identified subgroups differed across theoretically and empirically relevantconstructs in that the high anxious group reported significantly more maltreatment history,aggression, symptoms of ADHD and post-traumatic stress, and treatment involvement.Generally, the differences between the high anxious and the low anxious subgroups were thesame for males and females, but an important difference was that the female high anxioussubgroup reported being significantly more involved in treatment. In conclusion, the gainedsubgroups are in several ways, but not in all, in line with theories of primary and secondary psychopathy.

Normal subgroups can be thought of as the primary building blocks for decomposing mathematicalgroups into quotient groups. The properties of the resulting quotient groups are oftenused to determine properties of the group itself. This thesis considers normal subgroups of threedimensionalcrystallographic space groups that are themselves three-dimensional crystallographicspace groups; for convenience, we refer to such a subgroup as a csg-normal subgroup. We identifypractical restrictions on csg-normal subgroups that facilitate their tabulation. First, the point groupof an csg-normal subgroup must be a normal subgroup of the crystallographic point group of thespace group, which we refer to for convenience as a cpg-normal subgroup. For each of the cpgnormalsubgroups, which are all well known, we identify the abstract quotient group. Secondly,we identify necessary conditions on the sublattice basis of any csg-normal subgroup, and tabulatethe “normally supportive“ sublattices that meet these conditions, where some tables are symbolicforms that represent infinite families of sublattices. For a given space group, every csg-normalsubgroup must be an extension of such a normally supportive sublattice, though some normallysupportive sublattices may not actually support such extensions.

No description available.

In 1993, Muzychuk showed that the rational S-rings over a cyclic group Z_n are in one-to-one correspondence with sublattices of the divisor lattice of n, or equivalently, with sublattices of the lattice of subgroups of Z_n. This idea is easily extended to show that for any finite group G, sublattices of the lattice of characteristic subgroups of G give rise to rational S-rings over G in a natural way. Our main result is that any finite group may be represented as the automorphism group of such a rational S-ring over an abelian p-group. In order to show this, we first give a complete description of the automorphism classes and characteristic subgroups of finite abelian groups. We show that for a large class of abelian groups, including all those of odd order, the lattice of characteristic subgroups is distributive. We also prove a converse to the well-known result of Muzychuk that two S-rings over a cyclic group are isomorphic if and only if they coincide; namely, we show that over a group which is not cyclic, there always exist distinct isomorphic S-rings. Finally, we show that the automorphism group of any S-ring over a cyclic group is abelian.

No description available.

No description available.