A set S of vertices in a graph G is a total dominating set if every vertex of G is adjacent to some vertex in S. The total domination number γt(G) is the minimum cardinality of a total dominating set in G. The annihilation number a(G) is the largest integer k such that the sum of the first k terms of the non-decreasing degree sequence of G is at most the number of edges in G. In this paper, we investigate relationships between the annihilation number and the total domination number of a graph. Let T be a tree of order n<2. We show that γt(T)≤a(T)+1, and we characterize the extremal trees achieving equality in this bound.

A set S of vertices of a graph G is a dominating set if every vertex not in S is adjacent to a vertex of S and is a total dominating set if every vertex of G is adjacent to a vertex of S. The cardinality of a minimum dominating (total dominating) set of G is called the domination (total domination) number. A set that does not dominate (totally dominate) G is called a non-dominating (non-total dominating) set of G. A partition of the vertices of G into non-dominating (non-total dominating) sets is a non-dominating (non-total dominating) set partition. We show that the minimum number of sets in a non-dominating set partition of a graph G equals the total domination number of its complement Ḡ and the minimum number of sets in a non-total dominating set partition of G equals the domination number of Ḡ. This perspective yields new upper bounds on the domination and total domination numbers. We motivate the study of these concepts with a social network application.

A set S of vertices in a graph G is a total dominating set of G if every vertex of G is adjacent to some vertex in S. The minimum cardinality of a total dominating set of G is the total domination number of G. A graph is total domination edge critical if the removal of any arbitrary edge increases the total domination number. On the other hand, a graph is total domination edge stable if the removal of any arbitrary edge has no effect on the total domination number. In this paper, we characterize total domination edge critical graphs. We also investigate various properties of total domination edge stable graphs.

A set S of vertices in a graph G is a total dominating set of G if every vertex is adjacent to a vertex in S. The total domination number yγ t (G) is the minimum cardinality of a total dominating set of G. The total domination subdivision number sdγt (G) of a graph G is the minimum number of edges that must be subdivided (where each edge in G can be subdivided at most once) in order to increase the total domination number. Haynes et al. (J. Combin. Math. Combin. Comput. 44 (2003) 115) showed that for any tree T of order at least 3, 1 ≤sdγt (T)≤3. In this paper, we give a constructive characterization of trees whose total domination subdivision number is 3.

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Submitted in partial fulfillment of a Masters Degree in the Department of Educational Planning and Administration in the Faculty of Education at the University of Zululand, South Africa, 2007. / A number of sources and articles have been published on the subject of Total Quality Management (TQM). The majority of them have not been specifically targeted at how educators view TQM and how it could be used to improve teaching and learning in schools. The purpose of this study was to detennine the views of educators on TQM in secondary schools. The study aimed at finding out how TQM principles could be used to achieve quality teaching and learning. The focus was on TQM as a universal management tool for quality improvement in education. A questionnaire was administered to a total of eighty-eight respondents comprising ten principals, ten deputy principals, twenty heads of departments and forty-eight educators selected from ten secondary schools in the selected circuit. The data was analysed in percentages and recorded in tables. The results were also illustrated by means of the graphs to make interpretations easier.

Las artroplastias de las grandes articulaciones de carga, como la cadera y la rodilla, se ha demostrado que son procedimientos altamente exitosos para mejorar la calidad de vida en los pacientes con artrosis avanzada. Actualmente, existe discusión en si una previa artroplastia total de cadera (ATC) supone un factor de riesgo para el resultado funcional de una subsecuente artroplastia total de rodilla (ATR). No hemos encontrado ningún trabajo en la literatura que aclare esta controversia. Objetivo: Evaluar la influencia de una ATC primaria previa bien funcionante sobre el resultado funcional de una subsecuente ATR primaria ipsilateral. Material y Métodos: Estudio retrospectivo de casos y controles de 92 pacientes mayores de 60 años que se sometieron a una ATR primaria unilateral después de una ATC ipsilateral previa (grupo ATC-ATR) versus 92 pacientes que se sometieron solo a ATR (grupo ATR). Como instrumentos de medida para la evaluación clínica se emplearon las escalas Knee Society Score (KSS) para la rodilla y Harris Hip Score (HSS) para la cadera, los cuestionarios Reduced Western Ontario y MacMaster Universities (WOMAC) y el Short-Form 12 (SF-12) para la calidad de vida, y pruebas radiológicas complementarias. Resultados: El seguimiento medio después de la ATR fue de 7,2 años (rango 5-9) en el grupo ATC-ATR. No hubo diferencias significativas entre los grupos en el momento de la ATR. Las ganancias medias en el KSS fueron similares en ambos grupos. En el último seguimiento, no hubo diferencias estadísticamente significativas en las puntuaciones de WOMAC-dolor o SF12-físico, pero las puntuaciones de WOMAC-función (p= 0,003) y SF12-mental (p= 0,018) fueron significativamente mejores en el grupo de la ATR aislada. Tampoco hubo diferencias significativas en la alineación radiológica de la rodilla o en la posición de los componentes. Por causas asépticas, la supervivencia de la ATR a los 8 años en el grupo de ATR fue del 95,8% (IC del 95%: 87,8-100%) y del 96,6% (IC del 95%: 91,8-100%) en el grupo de ATC-ATR (p= 0,577). Conclusión: Una ATC previa, bien funcionante, no influye en el resultado funcional de una subsecuente ATR ipsilateral.

Research suggests declines in physical activity may occur after age 12. The purpose of this study was to determine the relationships between adolescent physical activity, BMI, and nutrition. Adolescents, ages 12-17 (N = 223), wore pedometers for 11 consecutive days and completed a nutrition survey, the Youth Adolescent Questionnaire. Activity levels did not differ among the ages of 12-17 year old adolescents, and boys were more active than girls. There was a low, but significant relationship between BMI and physical activity levels for both boys and girls. Energy intake was not related to BMI or physical activity levels in boys or girls.

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Inledning: Finansiella risker har blivit mer påtagliga i dagens samhälle och finansiell risk management har under senare år blivit ett mycket omtalat och studerat ämne. Det finns olika finansiella derivat som används för att säkra finansiella risker, det går att identifiera olika åsikter bland forskare om vilken påverkan dessa derivat har på risker inom företag. Valutaderivat är en av dessa säkringsinstrument som enligt teorin används för att reducera valutarisker. Problem: Huruvida valutaderivat reducerar den totala risken inom företag. Syfte: Undersöka om det finns ett riskreducerande samband mellan omfattningen på valutaderivat och företagens totala risk.  Teoretisk referensram: Teorier som används i uppsatsen beskriver valutarisker och vad de grundar sig i. Vidare tar den teoretiska referensramen upp hur valutarisker kan hanteras med hjälp av valutaderivat. Slutligen beskrivs vilket mått på risk undersökning använder, det vill säga standardavvikelsen i aktiekursen. Teoriavsnittet inkluderar även en djupare insyn i forskares delade åsikter om vilken effekt valutaderivat har på risk.  Metod: Studien använder sig främst av en kvantitativ metod där 45 internationellt verksamma företag har undersökts. Ett korrelationssamband samt polynomsamband testades mellan variablerna; företagens standardavvikelse i aktiekursen och omfattningen på valutaderivat i förhållande till nettoomsättningen. Även kvalitativa inslag i form av intervjuer inkluderades och bidrog till en metodtriangulering.  Slutsatser: Varken ett linjärt samband eller ett olinjärt samband gick att identifiera med hjälp av de statistiska uträkningarna. Den kvalitativa datan pekar på att valutaderivat kan minska företagens totala risk men för att kunna se en påverkan i aktiekursen behöver man rensa bort ett antal störande faktorer.