CENTRAL UNITS IN METACYCLIC INTEGRAL GROUP RINGS

In this article, we give a method to compute the rank of the subgroup of central units of ZG, for a finite metacyclic group, G, by means of Q-classes and R-classes. Then we construct a multiplicatively independent set u subset of Z(U(ZC(p,q))) and by applying our results, we prove that u generates a subgroup of finite index.

BASS CYCLIC UNITS AS FACTORS IN A FREE GROUP IN INTEGRAL GROUP RING UNITS

Marciniak and Sehgal showed that if u is a non-trivial bicyclic unit of an integral group ring then there is a bicyclic unit v such that u and v generate a non-abelian free group. A similar result does not hold for Bass cyclic units of infinite order based on non-central elements as some of them have finite order modulo the center. We prove a theorem that suggests that this is the only limitation to obtain a non-abelian free group from a given Bass cyclic unit. More precisely, we prove that if u is a Bass cyclic unit of an integral group ring ZG of a solvable and finite group G, such that u has infinite order modulo the center of U(ZG) and it is based on an element of prime order, then there is a non-abelian free group generated by a power of u and a power of a unit in ZG which is either a Bass cyclic unit or a bicyclic unit.

ALTERNATING UNITS AS FREE FACTORS IN THE GROUP OF UNITS OF INTEGRAL GROUP RINGS

Let G be a group of odd order that contains a non-central element x whose order is either a prime p >= 5 or 3(l), with l >= 2. Then, in U(ZG), the group of units of ZG, we can find an alternating unit u based on x, and another unit v, which can be either a bicyclic or an alternating unit, such that for all sufficiently large integers m we have that < u(m), v(m)> = < u(m)> * < v(m)> congruent to Z * Z.

Star-group identities and groups of units

Analogous to *-identities in rings with involution we define *-identities in groups. Suppose that G is a torsion group with involution * and that F is an infinite field with char F not equal 2. Extend * linearly to FG. We prove that the unit group U of FG satisfies a *-identity if and only if the symmetric elements U(+) satisfy a group identity.

Involutions and free pairs of bicyclic units in integral group rings

If * : G -> G is an involution on the finite group G, then * extends to an involution on the integral group ring Z[G] . In this paper, we consider whether bicyclic units u is an element of Z[G] exist with the property that the group < u, u*> generated by u and u* is free on the two generators. If this occurs, we say that (u, u*)is a free bicyclic pair. It turns out that the existence of u depends strongly upon the structure of G and on the nature of the involution. One positive result here is that if G is a nonabelian group with all Sylow subgroups abelian, then for any involution *, Z[G] contains a free bicyclic pair.

Locally nilpotent groups of units in tiled rings

We consider locally nilpotent subgroups of units in basic tiled rings A, over local rings O which satisfy a weak commutativity condition. Tiled rings are generalizations of both tiled orders and incidence rings. If, in addition, O is Artinian then we give a complete description of the maximal locally nilpotent subgroups of the unit group of A up to conjugacy. All of them are both nilpotent and maximal Engel. This generalizes our description of such subgroups of upper-triangular matrices over O given in M. Dokuchaev, V. Kirichenko, and C. Polcino Milies (2005) [3]. (C) 2010 Elsevier Inc. All rights reserved.

Group identities on symmetric units

Let F be an infinite field of characteristic different from 2, G a group and * an involution of G extended by linearity to an involution of the group algebra FG. Here we completely characterize the torsion groups G for which the *-symmetric units of FG satisfy a group identity. When * is the classical involution induced from g -> g(-1), g is an element of G, this result was obtained in [ A. Giambruno, S. K. Sehgal, A. Valenti, Symmetric units and group identities, Manuscripta Math. 96 (1998) 443-461]. (C) 2009 Elsevier Inc. All rights reserved.

The core characteristics and nursing care activities in psychiatric intensive care units in Sweden

Internationally, research on psychiatric intensive care units (PICUs) commonly reportsresults from demographic studies such as criteria for admission, need for involuntary treatment, andthe occurrence of violent behaviour. A few international studies describe the caring aspect of thePICUs based specifically on caregivers’ experiences. The concept of PICU in Sweden is not clearlydefined. The aim of this study is to describe the core characteristics of a PICU in Sweden and todescribe the care activities provided for patients admitted to the PICUs. Critical incident techniquewas used as the research method. Eighteen caregivers at a PICU participated in the study bycompleting a semistructured questionnaire. In-depth interviews with three nurses and two assistantnurses also constitute the data. An analysis of the content identified four categories that characterizethe core of PICU: the dramatic admission, protests and refusal of treatment, escalating behaviours, andtemporarily coercive measure. Care activities for PICUs were also analysed and identified as controlling– establishing boundaries, protecting – warding off, supporting – giving intensive assistance, andstructuring the environment. Finally, the discussion put focus on determining the intensive aspect ofpsychiatric care which has not been done in a Swedish perspective before. PICUs were interpreted asa level of care as it is composed by limited structures and closeness in care.

Parent’s experiences of feeding their preterm infant in Neonatal Units in Sweden. : Ethnographic design

Introduction: Studies have shown that having a preterm infant may cause stress and powerlessness for parents. It is important to support parents around the feeding situation, and that the Neonatal Intensive Care Unit (NICU) has appropriate space and place to help the family to bond to each other. For the healthcare professionals it is important to promote skin-to-skin contact and breastfeeding; particularly for preterm infants. There are many studies on parent’s experiences of NICUs and a few studies on parent’s experiences of feeding their infant in the NICU. Objective: The objective of this study was to explore parents experiences of feeding their infant in the NICU. Design: The study was conducted using an ethnographic design. Results: A global theme of ‘The journey in feeding’ was developed from four organising themes: ‘Ways of infant feeding’; ‘Environmental influences’; ‘Relationships’ and ‘Emotional factors’. These themes illustrate the challenges mothers reported with different methods of feeding. The environment had a big impact on parent’s experiences of infant feeding. Some mothers felt that breastfeeding seemed unnatural because their infant was so tiny but breastfeeding and skin-to-skin contact helped them to bond to their infant. The mothers thought it was difficult to keep up with the milk production by only pumping. Routines were not inviting parents to find their own rhythm. They also felt stressed about the weighing. Healthcare professionals had positive and negative influences on the parents. Conclusions: This study demonstrates that while all parents expressed the wish to breastfeed, their ‘journey in feeding’ was highly influenced by method of feeding, environmental, relational and emotional factors. The general focus upon routines and assessing milk intake generated anxiety and reduced relationality. Midwives and neonatal nurses need to ensure that they emphasise and support the relational aspects of parenting and avoid over-emphasising milk intake and associated progress of the infant