SbcCD has been shown to cleave a DNA hairpin formed by a palindromic DNA sequence on the lagging strand template of the E. coli chromosome. This activity was exploited to create a unique system for inducing a single site-specific DNA double-strand break (DSB) once per replication cycle. First, this work shows that the SOS response induced by this DSB is only essential for viability following multiple cycles of cleavage and repair. Next, the SOS-inducible inhibitor of cell division SfiA is shown to be dispensable for survival, despite demonstrating that cleavage of the palindrome causes both an increase in cell size and a delay in nucleoid segregation. A model of the E. coli cell cycle is presented to reconcile the observation that growth under chronic DSB induced conditions has no effect on generation time despite causing an increase in cell size. This system of DSB induction was then coupled with fluorescence markers on both sides of the palindrome to visualise the consequence of the DSB in vivo. Cleavage of the DNA hairpin by SbcCD in a recAmutant was used to selectively degrade the chromosome that replicated the palindrome on the lagging strand of replication, allowing two genetically identical sister chromosomes to be distinguished. This approach was used to show that chromosome segregation in E. coli is not random, but results in the segregation of lagging strand replicated DNA to mid-cell and leading strand replicated DNA to cell poles. Finally, this system for visualising the site of an inducible DSB was optimised for use in various other mutant backgrounds to allow the events of DSB repair to be dissected. This work provides a solid basis for further investigation into the relationship between replication, recombination and chromosome segregation in the model organism E. coli.

This project explores the contemporary history of segregation in Scottish prisons, focusing on measures of ‘special handling’ particularly the network of small units that was operative between the 1950s and the 1990s. Scotland has a complicated, troubling, idiosyncratic and, to a lesser degree, inspiring tradition of special handling measures, involving generic punishment blocks, anachronistic isolation units, highly innovative specialist units, ‘safe’ and ‘silent’ cells, and more collective segregation spaces such as vulnerable prisoners wings. Such sites have provoked considerable attention across public and political arenas; they have been sources of shame, pride, criticism and confusion; in specific penal moments, they have been experienced by prisoners (and officers) as warzones, sanctuaries, coffins and creative spaces; and, in terms of efficacy, they have both exacerbated and ameliorated the behavioural difficulties of the prisoners contained within them. The objectives of this research are (1) to chronologically map the evolution of key segregation sites, attending to the external pressures that have informed the policies, procedures and rules governing their protean use, (2) to explore the impact of particular environmental factors on the initial design, operation and, subsequently, the closure of these sites, and (3) to reflect on the relationship between space and the ways individuals have understood, coped with, and in various ways ‘acted-out’ their segregated confinement. Deciding who, how and why to segregate prisoners raises questions of a conceptual, operational, political, and moral nature. But deciding where to segregate prisoners situates such questions within the physical constraints and potentialities of space. By adopting a spatial-temporal approach, this research straddles disciplines, utilising the methods of penal history, prison sociology, and – though in a more approximate manner – the steadily burgeoning sub-discipline of carceral geography. Additionally, by marshalling a number of personal testimonies, this history attempts to capture the emotional resonances of segregation – how it feels to actually live and work in ‘prisons within prisons’.

Por meio da análise conceitual de territorialidade gay, verificar a dinâmica da produção e reprodução dos espaços gays na Rua Frei Caneca e na Avenida Vieira de Carvalho identificando assim os padrões com suas diferenças e semelhanças, limites e limitações nesses dois espaços, com enfoque ao primeiro caso, em que se dá um processo de renovação urbana. A pesquisa procura analisar até que ponto é possível falar em territorialidade gay e continuidade entre essas duas espacialidades multiterritoriais. Entre as questões a serem discutidas estão: como esses espaços são utilizados em diferentes momentos no dia e na semana; como se configura o padrão de consumo nesses dois espaços e por fim, como se mantém ou altera (e até que ponto) uma homogeneidade interna nos dois casos. / Through conceptual analysis of gay territoriality, check the dynamics of production and reproduction of gay spaces at Frei Caneca street and Vieira de Carvalho Avenue thus identifying the standards with their differences and similarities, boundaries and limitations in these two areas, with the first focus event, which occurs in a process of urban renewal. The research seeks to analyze to what extent it is possible to speak of gay and territorial continuity between these two spatialities multi-territory. Among the issues to be discussed are: how these spaces are used at different times in the day and week; the configuration of the consumption pattern in these two areas and finally, how to maintain or alter (and to what extent) an internal homogeneity in both cases.

The constructivist paradigm was used in the research study to focus on the challenges with affordable housing and concentrations of Housing Choice Voucher recipients in a county in Southern California. Viewed through the lens of Social Stratification posed by Max Weber, ones opportunities in life are based on his/her position of class, status and power, where by those with lower positions are excluded from opportunities. The literature discusses the goal of the Housing Choice Voucher Program is to deconcentrate poverty and provide opportunities to move to higher income areas in order to provide opportunities for social upward mobility. Residential socioeconomic segregation has considerable consequences for public health. Keeping in mind the sensitivity of this controversial topic, the researcher protected and maintained confidentiality through the research process. Thus, the member‑checking meeting in which the joint construction is shared with the study participants was held on a secured internet website. Data was gathered by interviewing a diverse group of participants from various levels of agency, including government agencies. This qualitative data was analyzed by identifying “units” of information that were then grouped into categories of topics relevant to the research focus. The result of the final data analysis was a formulation of sixteen categories which was then interpreted in the form of a social construction which concludes that there is a lack of affordable housing in the county, and concentrations of subsidized housing in lower income cities versus affluent cities is due to the demographics of cities as well as exclusion brought on by NIMBY occurrences. Implications for macro Social Work practice included community organizing and policy advocacy at various governmental levels. The termination of the study did not result in the study participants planning to move forward with the solutions that were formed during the research process. A “Thank you” email was sent to the participants with the final joint construction attached as well as the instructions on where to find the final report. The researcher invited the study participants to contact her in the future regarding any opportunities related to affordable and public housing in the County.

Silver (Ag) is a precious metal with a low stacking fault energy that is known to form copious nanoscale coherent twin boundaries during magnetron sputtering synthesis. Nanotwinned Ag metals are potentially attractive for creating new interface-dominated nanomaterials with unprecedented mechanical and physical properties. Grain-boundary segregation of solute elements has been found to increase the stability of interfaces and hardness of nanocrystalline metals. However, heavily alloying inevitably complicates the underlying deformation mechanisms due to the hardening effects of solutes, or a change of stacking fault energies in Ag caused by alloying. For the above reasons, we developed a microalloying (or doping) strategy by carefully selecting Cu as the primary impurity – a solute that is predicted to have no solid-solution strengthening effect in Ag when its content is below 3.0 wt.%. Neither will Cu affect the stacking fault energy of Ag at a concentration <1.0 wt.%. Moreover, Cu atoms are ~12% smaller than Ag ones, and Ag-Cu is an immiscible system, which facilitates the segregation of Cu into high-energy interface sites such as grain-boundaries and twin-boundary defects. In this thesis, large-scale hybrid Monte-Carlo and molecular dynamics simulations are used to study the unexplored mechanical behavior of Cu-segregated nanocrystalline nanotwinned Ag. First, the small-scale mechanics of solute Cu segregation and its effects on incipient plasticity mechanisms in nanotwinned Ag were studied. It was found that solute Cu atoms are segregated concurrently to grain boundaries and intrinsic twin-boundary kink-step defects. Low segregated Cu contents (< 1 at.%) are found to substantially increase twin-defect stability, leading to a pronounced rise in yield strength at 300 K. Second, atomistic simulations with a constant grain size of 45 nm and a wide range of twin boundary spacings were performed to investigate the Hall-Petch strength limit in nanocrystalline nanotwinned Ag containing either perfect or kinked twin boundaries. Three distinct strength regions were discovered as twin boundary decreases, delineated by normal Hall-Petch strengthening with a positive slope, the grain-boundary-dictated mechanism with near-zero Hall-Petch slope, and twin-boundary defect induced softening mechanism with a negative Hall-Petch slope. Third, by systematically studying smaller grain sizes, we find that the “strongest” size for pure nanotwinned Ag is achieved for a grain size of ~16 nm, below which softening occurs. The controlling plastic deformation mechanism changes from dislocation nucleation to grain boundary motion. This transition decreases to smaller grain sizes when Cu contents are segregated to the interfaces. Our simulations show that continuous Hall-Petch strengthening without softening, down to grain sizes as small as 6 nm, is reached when adding Cu atoms up to 12 at. %. For Cu contents ≥ 15 at. %, however, the predominant plastic deformation mechanism changes to shear-band induced softening. The present thesis provides new fundamental insights into solute segregation, and strengthening mechanisms mediated by grain boundaries and twin boundaries in face-centered cubic Ag metals, which is expected to motivate experimental studies on new nanotwinned metals with superior mechanical properties controlled by microalloying.

In two separate studies, I examine the relationship between skin tone and important psychological well-being, delinquency, and social integration outcomes for Blacks, testing not only if skin tone is important in determining these outcomes but attempting to disentangle the mechanism by which the inequality is produced. More specifically, using data from the National Longitudinal Study of Adolescent to Adult Health (Add Health), in study one I draw on important propositions of Agnew’s (1992) General Strain Theory to investigate the extent to which darker skin impacts youths’ feelings of strain, psychological well-being, and delinquency. The study found skin tone to be significantly associated with certain facets of well-being but surprisingly there were no direct effects on various types of strain. Skin tone is a strong predictor of one’s involvement in serious weapon violence, controlling for prior delinquency. Results also show that skin tone matters more for female adolescents’ odds of being suspended compared to their male counterparts, while certain forms of strain significantly impact the effect of skin tone on one’s involvement in delinquent activity. In study two, I continue my investigation of skin tone as an external or interracial source of discrimination using the National Survey of American Life (NSAL). In this study I am concerned with whether Blacks with darker skin tones are more likely than their lighter-skinned counter parts to live in neighborhoods that they perceive as more segregated and with fewer amenities and community resources. Although these data did not allow me to directly test how the respondents came to reside in their present community (i.e. racial steering or neighborhood choice), I examine skin tone discrimination as well as major types of everyday discrimination (e.g. being denied a bank loan or housing opportunity) experiences reported by Blacks. Overall, findings suggest that darker-skinned Blacks fare worse in regard to frequent experiences of skin tone discrimination from Whites. Skin tone is significantly related to respondent’s perceived seriousness of drug activity in their current neighborhood, suggesting that skin tone may have some impact on one’s perceived neighborhood quality. Further results, implications, and conclusions are discussed.

Research suggests that living in communities with high densities of persons from their own ethnic group improves the overall health of older Mexican Americans. One hypothesis is that residing in high ethnic density areas allows characteristics of Mexican culture such as strong social ties and social cohesion, to have a beneficial effect. The majority of investigations focused on ethnic density effects, however, have utilized relatively loose interpretations of what constitutes the appropriate social-geographic area to be studied. Moreover it is not clear how certain dimensions of residential segregation are protective or harmful toward health, particularly when measuring ethnic residential segregation from a geographic information systems (GIS) perspective. The effects of ethnic density and segregation have not been directly or quantitatively tested using the kind of multi-level methodology that can effectively capture data from both personal and environmental characteristics. The present study assessed how multiple geographic/neighborhood factors including ethnic density, neighborhood social cohesion, and social ties may serve as resources for health and health service use of older Mexican Americans. The study had three objectives: 1. To examine whether protective/deleterious effects of ethnic density exist when we use the more commonly used approach to measuring ethnic density (proportion of ethnic group within a specific census unit), and whether the ethnic density effect is increased when an alternative measurement approach (proximity weighted density) is used that relies on more than a single, specific census unit . 2. To examine how different dimensions of ethnic segregation are related to perceived social support, number of social ties, and perception of social cohesion in their neighborhood. 3. To examine whether or not social cohesion mediate the relationship between ethnic density or segregation and health status/health service use. The study represents a secondary analysis of data from the fifth interview wave of the Hispanic Established Populations for the Epidemiologic Study (H-EPESE; PI: Markides). Using geographic information systems (GIS), proximity weighted ethnic density and residential segregation indices were calculated, as well as more standard measures of density based on composition of the census tract in which participant lived. Since the H-EPESE dataset has a clustered structure where individuals are nested within neighborhoods, multilevel modeling techniques were employed. Results suggest that the several approaches here employed to measure ethnic composition of the local environment are complementary. First, the proportion of Hispanics in the neighborhood as defined by the use of census tracts, is both simple and the data easily accessible to researchers. This proportion, or what is often called density, was found to associate with several outcome measures in much the same way, and with similar proportions of variance as the more complex ways of method. The latter, however, made significant contributions that often were relatively independent of the census tract based proportions and thus add significantly to our understanding of the role of the ethnic neighborhood. These more complex measures, moreover, may potentially contribute even more: analyses using these newer approaches were limited by the lack of street address or census block data. Access to such data was not possible due to confidentiality issues surrounding the use of highly specific geographic information that could potentially identify the participant. Results did strongly suggest the value of a residential segregation index as a means of demonstrating that the ethnic environment and urban-rural composition of the residential environment contributes to our understanding of the importance of social coherence and social ties. It was found for example that older Mexican Americans who lived in neighborhoods with higher exposure segregation (i.e., neighborhoods where an individual from one particular racial/ethnic group has a higher probability of encountering members of another group, rather than from their own group) have higher depressive symptoms, as measured by the Center for Epidemiologic Studies Depression (CES-D) scale. This relationship was mediated by individual level data on perception of social cohesion. While in all cases causal interpretations were limited by the lack of a true experimental design the results generally do demonstrate the value of the newer, complementary, approaches to assessment of racial/ethnic density.

This research examines the role of five educational processes; curriculum, language, religion, culture, history, and geography and teachers, teacher education and teaching methods, on the perception of students of other constitutive people in Bosnia and Herzegovina and if it might have an impact on the longevity of the peace within the state. The importance of this research lays in the fact that BiH has experienced ethnic conflict in recent history which affected education and created ethnic division in the educational system. The aim of this research is to look at if the current educational system in BiH works on mending social cleavages that erupted as an aftermath of the war. By doing abductive qualitative field study and focusing on the educational system known as “two schools under one roof” findings show that all of the five previously mentioned processes carry to bigger or smaller extent threat and risk for social cohesion and peace in the country. Pupils are exposed to teachings filled with bias and prejudice and teachings that emphasize differences between different groups while ignoring similarities that could bring them together. Findings also suggest that the problem of the segregated educational system in BiH will most likely not end in the foreseeable future due to lack of will from teachers, parents, pupils and decision-makers.

<p>I uppsatsen undersöks vilken betydelse faktorer som familj, skola och vänner har för identitetsuppfattningen hos ungdomar med lindrig utvecklingsstörning, från deras eget perspektiv. Genom tematiska intervjuer med fem ungdomar som går i gymnasiesärskola har undersöks hur de såg på sin barndom, uppväxt, familjerelationer, kamrater och den egna självbilden. Resultatet har huvudsakligen analyserats utifrån E.H. Eriksons teori om identitetsutveckling. Resultatet visade att alla intervjupersoner upplevde att de under sin barndom hade kamrater och nästan alla hade en bra relation till sina föräldrar. Under tonåren förändrades detta och idag upplevde mer än hälften av de intervjuade att de inte hade några kamrater som de umgås med på fritiden och alla utom en ansåg att relationen till föräldrarna hade försämrats betydligt. Barndomsberättelserna vittnade om mobbing och många skolbyten hos en del av intervjupersonerna. Nästan alla ungdomar i studien förmedlade en bild av sig själva som osäkra på hur de ska bete sig vissa sammanhang. Analysen tyder på att ungdomar med en lindrig utvecklingsstörning kan ha svårigheter att förlika sig med att gå i särskola och att de inte vill förknippas med särskolans övriga elever. I min studie berättade mer än hälften av ungdomarna om sorg över att inte vara som alla andra ungdomar.</p>

<p>This study illuminates chosen parts of the present opportunities, in the Western World, for parents and children to choose which school the child will attend (freedom of choice), along with possible consequences that may follow. My research questions are: 1) Do tendencies show that freedom of choice leads to increased segregation, and if that is the case, how is it manifested and does it matter? 2) What relations between the student composition of schools and teachers' expectations and attitudes toward students are there? 3) Do the results from previous studies match with the result from my interviews? The methods used for answering the questions are literature studies and interviews made with six teachers who are working in two upper secondary schools in the northern part of Sweden, i.e. three from each school.</p><p>The result shows that freedom of choice, regarding schools, seems to lead to student compositions that contribute to increased segregation in societies. It leads to more homogenous student compositions, in the form of ethnicity and social class, in schools in general, with consequences like different expectations and attitudes among teachers depending on the status of the composition. A student composition of lower social class in general, seems to lead to lower expectations from teachers.</p>