Thesis advisor: Matthew S. Rutledge / In the past several decades, saving for retirement has significantly changed, with the large replacement of Defined Contribution for Defined Benefit plans, as well as the unreliability of Social Security given the aging population. This paper analyzes retirement wealth across three generational cohorts—Baby Boomers (1946-1964), Gen Xers (1965-1980), and Millennials (1981-2000)—in order to compare preparedness and determine whether or not younger cohorts have compensated for the future unreliability of other traditional retirement income sources. The results suggest that levels of retirement wealth do not significantly differ across cohorts at all age profiles. Therefore, younger generational cohorts have not increased the amount of personal saving in order to maintain their pre-retirement standards of living throughout retirement. These results indicate that a change in saving structure and policy may be necessary to ensure that younger cohorts retire out of poverty. / Thesis (BA) — Boston College, 2017. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Arts and Sciences Honors Program. / Discipline: Economics.

The purpose of this study was to identify teaching techniques that could be used in college classrooms for effectively teaching two different age cohorts: Baby Boomers and Generation X students. Baby Boomers are those people born between 1946 and 1964. The subsequent generation, known as Generation X, was born between 1965 and 1981. A multi-case qualitative study was designed to include interviews with faculty, focus groups with students, and classroom observations at three different community colleges in east Tennessee. Thirty-one faculty, ranging in age from 29 to 65, comprised the faculty panel. There were 48 student participants. Half of the 24 female students were Generation Xers. Of 22 male participants, 16 were Generation Xers. Classroom observations of nine different sections were conducted. These observations included traditional lecture classes, lab classes, and a couple of multimedia classrooms. Interviews with the faculty panel revealed almost diametrically opposite classroom behaviors between Baby Boomers and Generation X students. While older students are generally more motivated, focused, and come to class prepared to learn; younger students were reported to exhibit behaviors that are antithetical to these. Some younger students indicated that they preferred to work on teams with older students for these reasons. Additionally, effective teaching techniques for the two age cohorts were also discovered to be different. While both Boomers and Xers preferred real world examples to illustrate classroom theories, what was a relevant example for one generation was not always relevant for the other. Therefore, many instructors need to ascertain what is relevant in the Xers' world as constituted by the media, the Internet, and popular culture. The modern classroom needs a variety of teaching techniques to cater to different types of learners. Perhaps a model whereby older students mentor professional behavior for the younger, and the younger teach older students how to use computer technologies would be a better learning environment. Additionally, a third of the instructors interviewed have found that they need to be entertaining to hold the shorter attention spans of the younger student. Some type of visual component is becoming the norm in most classrooms, but there was not always agreement on which visuals were most effective for the two age groups. Baby Boomers generally preferred the board for transparency viewing or note taking in outline form Conversely, while some young students liked these methods, a greater number preferred watching videos. However, the videos had to be engaging and usually no longer than 20 minutes to be effective. Furthermore, 43% of the younger students value individual attention from their instructors, indicating that it can often make the difference between passing and failing a course. A third of the faculty also noted the younger students' hunger for attention. For instance, the eldest faculty member indicated, “So many Generation Xers are needy in terms of needing lots and lots of attention [because] a lot of my Generation X students are separated from their families.” Whatever the reasons, today's college instructors have a difficult task in assimilating the many learning styles and generational differences of age cohorts present in their classrooms. Not only do they have to stay informed in their academic domains and adapt their courses to multimedia and distance learning technologies, but they have to be entertaining for younger students to make the class interesting.

Les dimères chromosomiques se produisant lors de la réparation de chromosomes circulaires peuvent être dommageables pour les bactéries en bloquant la ségrégation des chromosomes et le bon déroulement de la division cellulaire. Pour remédier à ce problème, les bactéries utilisent le système Xer de monomérisation des chromosomes. Celui-ci est composé de deux tyrosine recombinases, XerC et XerD, qui vont agir au niveau du site dif et procéder à une recombinaison qui aura pour effet de séparer les deux copies de l’ADN. Le site dif est une séquence d’ADN où deux répétitions inversées imparfaites séparées par six paires de bases permettent la liaison de chacune des recombinases. Cette recombinaison est régulée à l’aide de FtsK, une protéine essentielle de l’appareil de division. Ce système a été étudié en profondeur chez Escherichia coli et a aussi été caractérisée dans une multitude d’espèces variées, par exemple Bacillus subtilis. Mais dans certaines espèces du groupe des Streptococcus, des études ont été en mesure d’identifier une seule recombinase, XerS, agissant au niveau d’un site atypique nommée difSL. Peu de temps après, un second système utilisant une seule recombinase a été identifié chez un groupe des epsilon-protéobactéries. La recombinase fut nommée XerH et le site de recombinaison, plus similaire à difSL qu’au site dif classique, difH. Dans cette thèse, des résultats d’expériences in vitro sur les deux systèmes sont présentés, ainsi que certains résultats in vivo. Il est démontré que XerS est en mesure de se lier de façon coopérative à difSL et que cette liaison est asymétrique, puisque XerS est capable de se lier à la moitié gauche du site prise individuellement mais non à la moitié droite. Le clivage par XerS est aussi asymétrique, étant plus efficace au niveau du brin inférieur. Pour ce qui est de XerH, la liaison à difH est beaucoup moins coopérative et n’a pas la même asymétrie. Par contre, le clivage est asymétrique lui aussi. La comparaison de ces deux systèmes montrent qu’ils ne sont pas homologues et que les systèmes Xer à seule recombinase existent sous plusieurs versions. Ces résultats représentent la première découverte d’un espaceur de 11 paires de bases chez les tyrosine recombinases ainsi que la première étude in vitro sur XerH. / The chromosome dimers produced during the repair of circular chromosomes can be harmful to bacteria by blocking the segregation of the chromosome and cell division. To overcome this problem, bacteria use the Xer system for the monomerisation of chromosome dimers. It has two components, XerC and XerD, which act on the dif site and complete a recombination that will lead to the separation of the two copies of the DNA. The dif site is a DNA sequence where two imperfect inverted repeats separated by six base pairs allow the binding of each recombinase. This recombination is regulated by the protein FtsK, an essential member of the cell division machinery. The Xer system has been well studied in Escherichia coli and has also been characterized in a variety of species, for example Bacillus subtilis. Furthermore, in certain species of Streptococcus, studies have identified only a single recombinase, XerS, which acts on an atypical site named difSL in order to monomerize dimeric chromosomes. Not long after, a second system using a single recombinase was identified in a group of epsilon-proteobacteria. This recombinase was named XerH and the recombination site, difH, was found to more similar to difSL than to the classical dif sites. In this thesis, results from in vitro experiments on both systems are presented, as well as some results from in vivo experiments. We show that XerS is capable of binding cooperatively to difSL and that this binding is asymmetrical. This is because XerS is able to bind to the left half of the site but not to the right half when they are separated. The cleavage by XerS is also asymmetrical, as it is more efficient on the bottom strand. As for XerH, its binding to difH is much less cooperative and doesn’t have the same asymmetry. But the cleavage is also asymmetrical like the one seen in XerS. Comparing the two systems show that they are not homologuous and that more than one version of Xer systems using a single recombinase exists. These results represent the first discovery of an 11 bases pairs spacer for tyrosine recombinase. It is also the first in vitro studies of XerH.

Les dimères chromosomiques se produisant lors de la réparation de chromosomes circulaires peuvent être dommageables pour les bactéries en bloquant la ségrégation des chromosomes et le bon déroulement de la division cellulaire. Pour remédier à ce problème, les bactéries utilisent le système Xer de monomérisation des chromosomes. Celui-ci est composé de deux tyrosine recombinases, XerC et XerD, qui vont agir au niveau du site dif et procéder à une recombinaison qui aura pour effet de séparer les deux copies de l’ADN. Le site dif est une séquence d’ADN où deux répétitions inversées imparfaites séparées par six paires de bases permettent la liaison de chacune des recombinases. Cette recombinaison est régulée à l’aide de FtsK, une protéine essentielle de l’appareil de division. Ce système a été étudié en profondeur chez Escherichia coli et a aussi été caractérisée dans une multitude d’espèces variées, par exemple Bacillus subtilis. Mais dans certaines espèces du groupe des Streptococcus, des études ont été en mesure d’identifier une seule recombinase, XerS, agissant au niveau d’un site atypique nommée difSL. Peu de temps après, un second système utilisant une seule recombinase a été identifié chez un groupe des epsilon-protéobactéries. La recombinase fut nommée XerH et le site de recombinaison, plus similaire à difSL qu’au site dif classique, difH. Dans cette thèse, des résultats d’expériences in vitro sur les deux systèmes sont présentés, ainsi que certains résultats in vivo. Il est démontré que XerS est en mesure de se lier de façon coopérative à difSL et que cette liaison est asymétrique, puisque XerS est capable de se lier à la moitié gauche du site prise individuellement mais non à la moitié droite. Le clivage par XerS est aussi asymétrique, étant plus efficace au niveau du brin inférieur. Pour ce qui est de XerH, la liaison à difH est beaucoup moins coopérative et n’a pas la même asymétrie. Par contre, le clivage est asymétrique lui aussi. La comparaison de ces deux systèmes montrent qu’ils ne sont pas homologues et que les systèmes Xer à seule recombinase existent sous plusieurs versions. Ces résultats représentent la première découverte d’un espaceur de 11 paires de bases chez les tyrosine recombinases ainsi que la première étude in vitro sur XerH. / The chromosome dimers produced during the repair of circular chromosomes can be harmful to bacteria by blocking the segregation of the chromosome and cell division. To overcome this problem, bacteria use the Xer system for the monomerisation of chromosome dimers. It has two components, XerC and XerD, which act on the dif site and complete a recombination that will lead to the separation of the two copies of the DNA. The dif site is a DNA sequence where two imperfect inverted repeats separated by six base pairs allow the binding of each recombinase. This recombination is regulated by the protein FtsK, an essential member of the cell division machinery. The Xer system has been well studied in Escherichia coli and has also been characterized in a variety of species, for example Bacillus subtilis. Furthermore, in certain species of Streptococcus, studies have identified only a single recombinase, XerS, which acts on an atypical site named difSL in order to monomerize dimeric chromosomes. Not long after, a second system using a single recombinase was identified in a group of epsilon-proteobacteria. This recombinase was named XerH and the recombination site, difH, was found to more similar to difSL than to the classical dif sites. In this thesis, results from in vitro experiments on both systems are presented, as well as some results from in vivo experiments. We show that XerS is capable of binding cooperatively to difSL and that this binding is asymmetrical. This is because XerS is able to bind to the left half of the site but not to the right half when they are separated. The cleavage by XerS is also asymmetrical, as it is more efficient on the bottom strand. As for XerH, its binding to difH is much less cooperative and doesn’t have the same asymmetry. But the cleavage is also asymmetrical like the one seen in XerS. Comparing the two systems show that they are not homologuous and that more than one version of Xer systems using a single recombinase exists. These results represent the first discovery of an 11 bases pairs spacer for tyrosine recombinase. It is also the first in vitro studies of XerH.

Emotions have become an important research topic in both the behavioural sciences and advertising. Nowadays, emotions are acknowledged as an important mediator of cognitive and behavioural consumer responses to advertising. Consequently, researchers in marketing and advertising have emphasised the need to consider emotions as a crucial factor in the advertising process. To test the viability of this assumption, an empirical research study was conducted at the Behavioural and Communication Research Division of the Bureau of Market Research (BMR). More specifically, the research study used a three–dimensional approach to measure generational differences in consumers’ emotional response to television advertisements. To capture immediate, positive and negative emotive responses towards a pre–selected test advertisement, the study used three research instruments, namely AdSAM, PrEmo (both non–verbal measurement instruments) and the List of Emotions (LoE) (verbal measurement instrument). Gauteng consumers (n = 102) who view television participated in the study, which revealed that ageing appears to be a significant antecedent in measuring emotive response to advertisements. In this regard, the study showed, among others, that Baby Boomers (older generation) were inclined to react to the advertisement in a different manner than younger generations (Millennials and Xers). For example, Baby Boomers found it easier to acknowledge higher levels of engagement with the test advertisement, as was noted in the high Arousal ratings. No significant differences were, however, evident between generations on the Pleasure dimension as all generations seem to have felt positively towards the test advertisement. Furthermore, although all generations felt positive emotive reactions when viewing the test advertisement, Millennials feel more Comfortable, whereas the Xers and Baby Boomers feel stronger Warmed emotions. Overall, older people tend to purposefully seek to experience positive emotions and avoid or limit negative emotions. In summary, both non–verbal and verbal measures reflected generational differences that seem to be more apparent when analysing negative emotions. The study also revealed that the AdSAM instrument appears to be advantageous when measuring emotions in television advertising due to its non–verbal properties. However, greater generational differences seem to be evident when emotions are measured with a verbal rather than non–verbal instrument. Against this background, certain recommendations for future research were made, amongst others, the need for further research on emotive reaction to television advertisements and the need for innovative research models that are customised for the diverse South African consumer market. / Thesis (M.A. (Research Psychology))--North-West University, Potchefstroom Campus, 2012.

Emotions have become an important research topic in both the behavioural sciences and advertising. Nowadays, emotions are acknowledged as an important mediator of cognitive and behavioural consumer responses to advertising. Consequently, researchers in marketing and advertising have emphasised the need to consider emotions as a crucial factor in the advertising process. To test the viability of this assumption, an empirical research study was conducted at the Behavioural and Communication Research Division of the Bureau of Market Research (BMR). More specifically, the research study used a three–dimensional approach to measure generational differences in consumers’ emotional response to television advertisements. To capture immediate, positive and negative emotive responses towards a pre–selected test advertisement, the study used three research instruments, namely AdSAM, PrEmo (both non–verbal measurement instruments) and the List of Emotions (LoE) (verbal measurement instrument). Gauteng consumers (n = 102) who view television participated in the study, which revealed that ageing appears to be a significant antecedent in measuring emotive response to advertisements. In this regard, the study showed, among others, that Baby Boomers (older generation) were inclined to react to the advertisement in a different manner than younger generations (Millennials and Xers). For example, Baby Boomers found it easier to acknowledge higher levels of engagement with the test advertisement, as was noted in the high Arousal ratings. No significant differences were, however, evident between generations on the Pleasure dimension as all generations seem to have felt positively towards the test advertisement. Furthermore, although all generations felt positive emotive reactions when viewing the test advertisement, Millennials feel more Comfortable, whereas the Xers and Baby Boomers feel stronger Warmed emotions. Overall, older people tend to purposefully seek to experience positive emotions and avoid or limit negative emotions. In summary, both non–verbal and verbal measures reflected generational differences that seem to be more apparent when analysing negative emotions. The study also revealed that the AdSAM instrument appears to be advantageous when measuring emotions in television advertising due to its non–verbal properties. However, greater generational differences seem to be evident when emotions are measured with a verbal rather than non–verbal instrument. Against this background, certain recommendations for future research were made, amongst others, the need for further research on emotive reaction to television advertisements and the need for innovative research models that are customised for the diverse South African consumer market. / Thesis (M.A. (Research Psychology))--North-West University, Potchefstroom Campus, 2012.

L'état circulaire du chromosome bactérien pose un problème particulier lors de la réplication. Un nombre impair d'événements de recombinaison homologue donne des chromosomes dimères concaténés qui ne peuvent pas être divisés en cellules filles. Pour résoudre ce problème, les bactéries ont mis au point un mécanisme de résolution des dimères basé sur un système de recombinaison spécifique au site. Ceci est effectué par le système Xer/dif. Dans ce système, les protéines Xer effectuent une réaction de recombinaison dans le site dif au niveau du septum cellulaire immédiatement avant la division cellulaire. Dans la plupart des bactéries, cette réaction est effectuée par deux recombinases, XerC et XerD. Cependant, Streptococcus suis, un agent pathogène zoonotique important utilise un système de recombinaison différent, constitué d'une seule enzyme recombinase appelée XerS, qui catalyse la réaction de recombinaison dans un site dif non conventionnel. Pour caractériser le mode de clivage de XerS, des expériences EMSA ont été réalisées en utilisant des fragments de PCR marqués par HEX et des "suicide substrates". Nos données suggèrent que 1.) XerS est capable de lier la séquence entière de difSL; 2.) XerS lie plus efficacement le côté gauche des mutants difSL incomplets que le côté droit; 3.) XerS coupe les brins supérieur et inférieur du site difSL, avec une réaction plus efficace au bas. 4.) Modifications des nucléotides de la région la plus externe ou de la région centrale changent les préférences de clivage. 5.) XerS n'a montré aucune activité spécifique sur un autre site dif non conventionnel des Firmicutes, 6.) XerS interagit avec la sous-unité FtsK-y. L'ensemble des résultats présentés permet de mieux comprendre le fonctionnement de la recombinaison XerS dans le système de recombinase unique de Streptococcus et comment cette recombinaison est régulée par des facteurs de l'hôte. / The circular state of the bacterial chromosome presents a specific problem during replication. An odd number of homologous recombination events results in concatenated dimer chromosomes that cannot be partitioned into daughter cells. To solve this problem, bacteria have developed a mechanism of dimer resolution based on site-specific recombination system. This is performed by the Xer/dif system. In this system, the Xer proteins perform a recombination reaction in the dif site at the cell septum immediately prior to cell division. In most bacteria this reaction is performed by two recombinases, XerC and XerD. However, an important zoonotic pathogen; Streptococcus suis harbors a different recombination system, composed by a single recombinase enzyme called XerS, that catalyzes the recombination reaction in an unconventional dif site; difSL. A region characterized by two imperfect inverted repeat regions that flank a central region of 11 bp.To characterize the mode of cleavage of XerS, EMSA experiments were performed by using HEX-labelled PCR fragments and “nicked suicide substrates”. Our data suggests that; 1.) XerS is able to bind the entire difSL sequence; 2.) XerS binds more efficiently the left half side on incomplete difSL mutants than the right half side; 3.) XerS cleaves both the top and bottom strands of the difSL site, with a more efficient reaction at the bottom strand; 4.) Nucleotides at the outermost region of a T rich region seem to be determinant for binding selectivity and modifications of the extra spacing between the inverted repeat arms as well as length modifications of the central region change cleavage preference. 5.) XerS did not show any specific activity on another unconventional dif site in Firmicutes, as tested on difH. 6.) XerS interacts with FtsK-y subunit. This research aims to understand how XerS recombination works in the single recombinase system of Streptococcus and how this recombination is regulated by host factors. Exploration of these recombinases will provide a better understanding of the mechanisms of DNA exchange and genome stability in bacteria. It can also increase our knowledge of the evolution and speciation of recombinogenic bacteria.