On minimal coverings of groups by proper normalizers

For a finite group $G$, a {\it normalizer covering} of $G$ is a set of proper normalizers of some subgroups of $G$ whose union is $G$. First we give a necessary and sufficient condition for a group having a {\it normalizer covering}. Also, we find some properties of $p$-groups ($p$ a prime) having a normalizer covering. For a group $G$ with a normalizer covering, we define $\sigma_n(G)$ the minimum cardinality amongst all the normalizer coverings of $G$. In this article, we show that if $G$ is a $p$-group with a normalizer covering, then $\sigma_n(G)=p+1$ or 5. Finally, for any prime $p$ and positive integer $k$, we construct a solvable group $G$ with $\sigma_n(G)=p^k+1$

Support in Clinical Settings as Perceived by Nursing Students in Iran: A Qualitative Study

Background: Although support is one of the most substantial needs of nursing students during clinical education, it is not clearly defined in the literature. Objectives: The current study aimed to explore the concept of support in clinical settings as perceived by nursing students. Materials and Methods: A qualitative content analysis was used to explore the meaning of student support in clinical settings. A purposive sampling with maximum variation was used to select the participants among bachelor nursing students in the nursing school of Babol University of Medical Sciences in the north of Iran. Semi-structured interviews were conducted to gather the perceptions and experiences of seventeen nursing students. Conventional content analysis was applied to analyze the data. Results: In the current study, the main theme, nurturance, was emerged with seven subthemes of humanistic behavior with the student, respectful communication with students, accepting the student in the clinical setting, sustaining confidence, need based supervision, accepting the profession in the society and empowerment. Conclusions: Nursing students support in the clinical education requires a nurturing care; a care that leads to the sense of worthiness and respectability in students and contributes to the improvement of their clinical abilities

Minimal coverings of completely reducible groups

Let G be a group that is a set-theortic union of finitely many proper subgroups. Cohn defined σ(G) to be the least integer m such that G is the union of m proper subgroups. Determining σ is an open problem for most non-solvable groups. In this paper we give a formula for σ(G), where G is a completely reducible group

The Effect of Experience on Recognition of Mother’s Voice in Preterm Infants

Background: According to existing theories, supportive cares provided through specific kinds of stimuli affect the growth, development and neurobehavioral functioning of preterm infants. Some of the studies indicate that the fetal heart rate response to mother’s voice begins in the week 32 of pregnancy. However, the fact that whether preterm infant is able to recognize mother’s live voice from the voice of a stranger woman is unknown. Objectives: The present study aimed to compare the effects of mother’s voice and a stranger’s voice on the heart rate of preterm infants hospitalized in a neonatal intensive care unit (NICU). Methods: In a clinical trial study, 66 preterm infants hospitalized in the NICU were randomly assigned into three groups of 22 (i.e. mother’s voice and stranger’s voice groups and a silent group). The infants’ heart rates were recorded by a monitoring system in all of the three groups each five minutes for 30 minutes overall (10 minutes before, during and after the intervention) in three consecutive days. Both one-way and repeated measures analysis of variance were used to analyze the data in terms of significant differences. Also, the chi-square test and analysis of variance were used to compare the demographic variables of the groups. Results: The heart rate of the infants in the mother’s voice group, stranger’s voice group and the silent group were 133.99 � 2.72, 134.26 � 2.43 and 137.94 � 2.92 per minutes, respectively (P > 0.588) and changed to 143.42 � 2.85, 133.22 � 2.15 and 138.28 � 2.21, respectively (P = 0.016). Moreover, the infants’ heart rates were respectively 136.87�3.38, 132.68�2.22 and 138.19�2.65 per minutes, 10 minutes after the intervention (P > 0.345). Conclusions: No significant difference was found between the mean heart rates of the three groups neither before, nor 10 minutes after the intervention. However, a significant difference was observed among the three groups during the intervention. Therefore, we can conclude that the preterm infants can recall and differentiate their mothers’ voice from the voice of a stranger. Then, an opportunity can be provided during the developmental care for the infants to hear their mothers’ voice

AN ALEXANDROFF TOPOLOGY ON GRAPHS

Abstract. Let G = (V, E) be a locally finite graph, i.e. a graph in which every vertex has finitely many adjacent vertices. In this paper, we associate a topology to G, called graphic topology of G and we show that it is an Alexandroff topology, i.e. a topology in which intersection of each family of open sets is open. Then we investigate some properties of this topology. Our motivation is to give an elementary step toward investigation of some properties of locally finite graphs by their corresponding topology which we introduce in this paper